One of the most memorable duelists from the Yu-Gi-Oh! anime is Mai Valentine, who viewers were introduced to during the first arc of the show in Duelist Kingdom. While she wasn't a part of the main cast, she certainly had a good amount of screentime, and many of her duels were featured on the show.
However, some of these duels are a lot better than others. While none of Mai's duels are particularly bad, some are highlights, while others tend to fade to the background. In addition, some of these duels happen while one of the participants is on the verge of passing out for most of it.
Her Second Waking The Dragons Duel With Joey
The second time that Joey and Mai face off during the Waking the Dragons arc, Joey had just gotten through a duel that had essentially devolved into a fistfight between him and Valon, so he was obviously exhausted.
However, there was no way out of a duel with Mai, so he proceeded. The duel doesn't last long before he collapses from exhaustion, which is why this duel takes the bottom spot on the list. There isn't very much to this match at all. It ends a couple turns in, and is about as anti-climactic as it can get.
Tea In Duelist Kingdom
The duel between Mai and Tea is nice, though it isn't anything too special. Yugi is in complete shock from everything that happened during his duel with Kaiba in order to enter the castle, and can barely speak. Fighting over control of your body with a completely separate person living in your head cannot be fun.
In the end. as he can't accept them, Tea battles on behalf of Yugi for some star chips that Mai won for him to get him into the castle. It's fun, and Mai surrenders despite having the cards she needs to defeat Tea. It's a good character moment for both women that shows how they've grown through the season.
Jean Claude Magnum In Battle City
Unfortunately, it's pretty rare that Mai Valentine wins games. Despite having one of the better decks of the original series, the writers seem intent on making sure that she always loses. As such, one of her few wins comes from Jean Claude Magnum, a man from her past who comes back to duel her before the Battle City finals.
After she defeats him, he proceeds to kidnap her before she escapes. And then the entire crew moves on like literally nothing happened, because that's just how filler arcs work.
Joey In Duelist Kingdom
The duel between Mai and Joey during Duelist Kingdom is the first sign of Mai realizing that maybe the gang really do want to be her friends, but this realization doesn't come until she is defeated by Joey using the only strategy that he has in Duelist Kingdom, Time Wizard.
After seeing through her perfume tactics to pretend that she has ESP, Joey rolls the dice on using Time Wizard and succeeds, taking out the Harpies and aging Baby Dragon up into Thousand Dragon.
Her First Waking The Dragons Duel With Joey
Mai's first showdown with Joey during the Waking the Dragons arc is a lot better than the second. Besides being super action-packed, this is one of Mai's best duels, as the raw power of her deck is showcased pretty well here. If it weren't for Hermos just popping into Joey's deck, he probably would have gone down very quickly.
The only downside to this duel is the fact that it doesn't have a winner. Valon breaks the Seal of Orichalcos before the winner can be declared because he's worried that Mai will lose, so this duel is never resolved. If it had a winner, it might have taken the top spot on the list.
Yugi In Duelist Kingdom
Mai's duel with Yugi in Duelist Kingdom is a solid one. Yugi is having an internal battle with Atem following his willingness to let Kaiba die in their last duel, so he's anything but focused on his current duel.
Mai begins to take a pretty easy lead, but then snaps Yugi out of it. She doesn't want to win against Yugi unless he's at his best. This speaks to him, and he manages to pull it together, which, of course, results in Mai losing. She probably should have just let him lose. Either way, it's a fun duel to watch. But it isn't her best.
Marik In Battle City
This duel is incredibly frustrating because by all accounts Mai won this duel. Even with Marik using the Shadow Realm to mess with her mind, Mai outduels Marik from start to finish in this match. The only reason that she loses is that The Winged Dragon of Ra decided to magically create an ancient Egyptian poem that must be read in order to summon it.
Of course, once Mai summons the creature, Marik recites it and it switches to his side of the field. This duel best shows off Mai's dueling skill. She should have won this one, and it's unfortunate that the writers refused to let it happen.