Rivalries are an essential part of the Pokémon experience. You get your first partner Pokémon and set off on your journey with a dream in your heart, but along the way, you meet another Pokémon Trainer who likely has a similar dream, and a fierce competition to be the best ensues. Ash and his friends are no exception. Pokémon the Series boasts 25 years of these rivalries. Some of them are friendly. Some…might get a little more heated. But all of them inspire Ash and his friends to work harder, to get stronger, and to achieve their goals. Don’t forget to watch the final 12 episodes of Pokémon the Series, titled “To Be a Pokémon Master,” on Netflix to see how one of the most iconic relationships in the entire series plays out. Here are ten of its greatest rivalries.

Paul and Ash

There are dozens of rivalries through Pokémon animation’s decades-long history, but Paul easily wins the title of most unlikeable rival. When Ash first meets Paul, the Pokémon Trainer from Sinnoh catches three Starly and releases two, deeming them too weak for his team (“When Pokémon Worlds Collide!”). He later calls Ash’s Turtwig pathetic after defeating it in battle (“Different Strokes for Different Blokes”) and even insults Gym Leader Maylene after he defeats her (“Lost Leader Strategy”). But perhaps his cruelest display of indifference is overtraining Chimchar until Ash and Pikachu intervene. Ash and Pikachu manage to bring Chimchar to the Pokémon Center for rest before Paul eventually abandons the Pokémon.

Ash’s kindness, care, and love for his Pokémon shine in juxtaposition to Paul’s coldness, prompting Ash to invite Chimchar to join his team (“Smells Like Team Spirit”). While it takes Chimchar some time to recover from the harsh training Paul subjected it to, Chimchar and Ash’s bond grows strong and it evolves (literally and figuratively) into a powerful Pokémon, forcing even Paul to acknowledge its strength. While Paul will never be a warm, friendly rival, his treatment of his Pokémon and the other Pokémon Trainers he comes into contact with serves as an excellent reminder of what not to do. And watching Ash finally defeat Paul is immensely satisfying (“Battling a Thaw in Relations!”). Of course, the fact that Paul eventually helps Ash prepare for his big battle against Leon in the World Coronation Series does offer some redemptive value to Paul’s previously a-Paul-ling behavior (“Friends, Rivals, Lend Me Your Spirit!”).

Alain and Ash

When it comes to battle prowess, Alain is one of Ash’s greatest rivals. In fact, Ash never successfully defeats Alain in battle. Alain is a complicated figure, driven by passion for researching Mega Evolution, seeking out Mega Stones. When we first meet Alain, he’s working as Professor Sycamore’s assistant. Team Flare’s Lysandre successfully tricks Alain into working with him, but despite the fact that he’s assisting a villainous operation, Alain’s not a bad person.

In Ash and Alain’s first meeting, they inevitably battle, and Alain and his Charizard defeat Ash and his Greninja (“A Meeting of Two Journeys!”). Later, Ash encourages Alain to enter the Kalos League (“The Synchronicity Test!”), which Alain does because he wants to battle Ash again. Both Ash and Alain share a passion for battling, and both of them are fine with losing if it means they get to enjoy an excellent battle in the process. Alain is so intrigued by Ash and Greninja’s relationship and unique form—called Ash-Greninja—that he doesn’t seem to care about winning the Kalos League. But after an intense and prolonged battle with Ash, Alain and his beloved Charizard do exactly that, earning the title of Kalos League Champion (“Down to the Fiery Finish!”).

Persian and Meowth

The battle for the position of “Top Cat” is fierce, at least on the part of Team Rocket’s Meowth. It’s difficult to say how Giovanni’s Persian feels about Meowth, especially given that Meowth is the only one of the duo capable of human speech. But based on Persian’s smug expression and tendency to taunt Meowth by sticking out its tongue at him (“Pearls are a Spoink’s Best Friend”), Giovanni’s Persian does seem to return Meowth’s dislike to some extent. One of Meowth’s fondest dreams is to replace Persian as Giovanni’s Pokémon companion, a desire that Meowth frequently mentions and that even occurs in a dream after Mismagius uses Hypnosis on him (“Malice in Wonderland!”). It doesn’t help that Meowth lost Meowzie—the Meowth he fell in love with a long time ago—to another Persian. While these rivals never get the showdown Meowth seems to yearn for, it is one of the series’ most enduring rivalries.

Zoey and Dawn

Rivalries come in all shapes and sizes, and it’s safe to say that Zoey and Dawn are some of the kindest and most helpful rivals in the entire series. The pair first meet when Zoey’s Glameow returns Dawn’s lost choker just before Dawn’s first Pokémon Contest (“Mounting A Coordinator Assault!”). And Zoey compounds that kindness later by helping Dawn with her hair just before they take the stage. This sets the pattern for a friendship and rivalry that inspires them both to put their best feet forward. When Zoey sprains her ankle, Dawn helps her out (“A Stand-Up Sit-Down!”). It’s Zoey who teaches Dawn about move combinations and helps her develop some of her own. It’s also Zoey who recommends that Dawn enter the Hearthome City Tag Battle Competition to help improve her confidence in battles, which are an important part of Pokémon Contests. Over and over again, the pair prove that win or lose, they’re both always cheering each other.

Butch & Cassidy and Jessie & James

When it comes to a battle of Team Rocket versus Team Rocket, it’s safe to say that Jessie and James have won our hearts, but Butch and Cassidy are arguably the more effective Pokémon thieves. The two Team Rocket teams have a lengthy history characterized by intense competition and animosity hearkening back to their days at the Team Rocket training academy where they were fierce rivals (“Training Daze”). While Butch and Cassidy seem to be Giovanni’s favorites, successfully running a fake Pokémon breeding center (“The Breeding Center Secret”) and even kidnapping Professor Oak (“Oaknapped!”), when it comes to sheer entertainment value, nothing and no one can defeat Jessie and James.

Aria and Serena

While most rivalries occur between Pokémon Trainers on somewhat even footing, Serena and Aria’s relationship is a notable exception. When we first meet Serena, she has no real dream beyond reuniting with a boy she met many years ago at a Pokémon summer camp. Meanwhile, Aria is the Kalos Queen, and is considered to be the very best Pokémon performer in all Kalos. And when Serena finally decides that she too wants to become a Pokémon performer, she has a long, difficult journey ahead. But Serena draws inspiration from watching Aria perform and recognizing the joy that Aria inspires in her audience. It would be easy for Aria to dismiss Serena, to be so caught up in her own career and responsibilities that she doesn’t have time for a newbie Pokémon performer. Instead, Aria helps Serena train, offering her advice (“Battling with Elegance and a Big Smile!”). She even acknowledges Serena as a rival (“Performing a Pathway to the Future!”) which may be the greatest gift of all. As we know from watching other Trainers compete, a good rival can sometimes be the perfect motivation to become the very best, like no one ever was.

Sawyer and Ash

While many of Pokémon animation’s most memorable rivals are undeniably arrogant, eager to proclaim their prowess in battle and as performers, Sawyer stands out for his humility. From the very beginning, Sawyer accepts defeat in battle with grace, soliciting advice from his opponent. In fact, it’s rare to see the green-haired Pokémon Trainer without his notebook in hand, so eager to improve that you often see him smiling after losing a battle because he gained knowledge in the process. We watch Sawyer lose a lot of Pokémon battles. He loses a Gym Battle against Valerie (“A Fashionable Battle!”), and Ash defeats him multiple times (“Rivals: Today and Tomorrow”) and (“A Meeting of Two Journeys!”). And then there comes a day when Ash and Sawyer face each other and the outcome is very different (“A Full-Strength Battle Surprise!”) and it’s enormously satisfying to see Sawyer’s hard work pay off. Ash is undeniably the protagonist, but you never want to root against Sawyer, especially seeing how hard he’s worked with his Pokémon and seeing how far he’s come from the long string of losses he first endured.

Guzma and Professor Kukui

The rivalry between Guzma, Alola’s leader of the moderately villainous Team Skull, and Professor Kukui, Alola’s Pokémon Professor and a teacher at the Pokémon School, is complicated and steeped in history. It also says a lot about how people can be shaped by disappointment and lack of confidence. Professor Kukui is a helpful and beloved figure in Alola, running the school, organizing a Pokémon League, and secretly moonlighting as the Masked Royal. Guzma, however, runs a band of misfits in Po Town, devoted to harassment, mockery, and destruction. But it doesn’t take very long to realize that Guzma’s misanthropic attitude and his dislike of Professor Kukui don’t actually have all that much to do with Professor Kukui at all. When they were young and both apprentices with Kahuna Hala, Kukui defeated Guzma in battle, and instead of committing to growing stronger, Guzma rebelled against Hala, Kukui, and Z-Rings (“League Offenders and Defenders!”).

For years, Guzma held onto that grudge, but when Professor Kukui decides to create an Alola Pokémon League, Guzma feels compelled to intervene with the intention of destroying the League before it can get off the ground (“The Dealer of Destruction!”). Answering Kukui’s challenge to compete in the Pokémon League, Guzma is determined to destroy it from the inside. But the competition instead serves up some difficult truths, and Guzma decides, like Professor Kukui and Ash, to let go of his cowardice and instead train himself and his Pokémon to become stronger. Guzma and Kukui may never be besties, but Alola is undeniably a more colorful and interesting place because they both live, train, and compete there.

Leon and Ash

Maybe it’s the fact that Leon is Ash’s final rival in a 25-year history. Maybe it’s the fact that defeating Leon is the key to achieving Ash’s lifelong dream. Facing off against a Champion is no small feat, but the fact that Leon serves as both mentor and rival to Ash makes their relationship extra special. When they first meet, Leon gives Ash his very first Dynamax Band as well as some much-needed advice about how to defeat a rampaging Drednaw (“The Climb to Be the Very Best!”). Of course, Ash challenges the Galar region Champion, as expected, and Leon graciously accepts this challenge.

Beyond their seemingly endless enthusiasm for Pokémon battles, Ash and Leon share an almost childlike appreciation for everything related to Pokémon. They’ll win a battle and immediately set off for special training, and both prove themselves willing to risk their own lives to help Pokémon in need (“Meeting Up with the Monarch!”). So, it’s inevitable that Leon and Ash’s final showdown for the title of Champion of the World Coronation Series has a lot of emotional weight behind it (“A Flood of Torrential Gains!”). With many of Ash’s friends, rivals, and Pokémon from his many adventures looking on, Ash defeats Leon to win the coveted title of Monarch (“Partners in Time!”) in a moment none of us will ever forget.

Gary Oak and Ash

In the beginning there was Ash and Pikachu and…Gary Oak. There’s no denying that Gary had the upper hand in their highly memorable first interaction (“Pokémon – I Choose You”). He has Pokémon, cheerleaders, and a grandfather who happens to be a Pokémon Professor, while Ash is standing there in pajamas, seemingly confused by about half of what Gary has to say. Gary proclaims his intention of becoming a Pokémon master and bringing pride to their hometown before taking off in a sporty red convertible. Ash sets off on his journey—on foot—with the same dream, and their future interactions will act as an indicator of how both have evolved as Trainers and people. So, it’s only fitting that at the very end, after 25 years of battles and boasting, in the end there’s Ash and Pikachu and…Gary Oak. In the final episode of the 12-episode series “To Be a Pokémon Master,” Ash and Gary reunite in Pallet Town (“The Rainbow and the Pokémon Master”). You’ll have to watch on Netflix to learn what they have to say, but be sure to have some tissues handy.