My favorite character from the original Yu-Gi-Oh! show/series would be Yugi because of the fact that he had a excellent character design clothing wise and I liked his militiaman puzzle form. 

My favorite character from the original would be Joey. He makes the best dope / rape faces ever ! My favorite characters from the more recent series would have to be Yusei and Aporia from Yugioh 5d's. 

My Favorite Yu-Gi-Oh Character would have to be Yusei hands down. He is actually good at dueling for the first part. He does not give crap to the authorities, and he rides a motorcycle while he duels.

First off i only watch the old Yu-Gi-Oh I don't like the way the new one look and I don't like the direction it's going but I loved the old Yu-Gi-Oh that said my favorite characters are Maximillion Pegasus and Yugi Mutou but my number one favorite character would have to be Seto Kaiba.

My favorite Yu-Gi-Oh character is Marik because he's so cunning and evil.

I'd pretty much only watched the first Yu-Gi-Oh series, because let's face it, it's the best one.

Anyways, I'd say Bakura/Yami Bakura. I just love his character, his design, how he duels, pretty much everything about this character.

Yugioh-Joey: I like hi use of Gamble cards

Without a doubt that would have to be Wevil. Simply because I'm an insect user and he's not afraid to do what needs to be done to try and win, I.e. Cheat. I mean I never cheated in yu-gi-oh against my friends but, then again, I never needed to. My mill deck was supreme. Too bad I have no idea what half the cards now-a-days do...

Definitely Yami. He has his head in the game, and is not as annoying as little Yugi. Tristan is pretty cool though. Everyone sucks from GX and beyond though. 

I changed my mind. I am going with Younger Yugi. The innocence of the kid that solved the Millennium Puzzle is just done so perfectly. 

My favorite character from the Yu-Gi-Oh series has to be Mr. Joey Wheeler. He is like a big brother who is really protective and can be dumb in his moments. Almost every Joey Wheeler is either funny or heart touching to me. Not to mention that I still love those moments when he was in a dog suit for Seto Kaiba.

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Personally my favorite is joey wheeler just cuz he has cool hair, and his voice is catchy.

That, and because his voice sounds nice when he is nyaning.

Barathemos : Would have to be yusei fudo. He probably has the best main monster card out of all other characters to date.

Really hard to choose only one. I can name a bunch of good ones, including Reiji, Seto, Shun, Yugo, IV and Kaiser.

I left one out of the list on purpose, and that is Jack Atlas. Why I left him out? Because he stands out from the rest. Either in 5D's or ARC-V, he's the most baddass character, and deploys such ferocity while dueling that you cannot hate him.

My favorite might not be very popular, but I'm actually quite a fan of Carly Carmine during the first season of 5Ds. She helps Jack to see there's more to life than clawing your way to the top. She's quite capable at, if not dueling, investigative journalism trying to get to the heart of everything going on in the series. When she dies as comes back she finds some confidence in herself but is pretty much still the same person from before. Instead of trying for revenge she just wants to be able to be together and becoming a dark king and queen is the only way she can see, since they had no way to know they'd come back after it was all over. Even then, in the end, she was willing to sacrifice herself when she was perfectly capable of defeating Jack Atlas and leading the dark signers to victory.

Other characters might have flashier designs, or be referred to as stronger duelists, but I think she had some of the best character development  and storyline of any yugioh franchise. It's a shame once season 2 rolled around they completely ignored their story to set up more of a traditional harem structure.

Yami. It has always been him. Because he was the main character who had it all. Even if worse comes to worse dueling wise he would always find a way to win. And I think that is what I loved about him a lot. I did like Joey too he was one of the funniest characters there. XD