My Yugioh knowledge is rusty but lets see here.
1. Yusei. Crazy hair, check, odd sense of fashion, check, very cool deck, check. Always played smart, never arrogant, kept his cool but did not have hax like Atem/Yugi.
2. Atem/Yugi. from my memory won every duel except the forfeit to Kaiba due to threats against his own life. Oh and the final duel vs each other.
3. Kite. always used overwhelming power and to good effect but also remembers to use balance.
4. Kaiba. How can you not love this guy? He's got the money, he's got the cards, he's got the corporate empire and at one point green hair. Oh and is the only possessor of the Blue Eyes and he knows how to use them!
5. Chazz. Having a streak of rivals arent I? I did not finish GX, I watched until about half of season 2 and then stopped. But what always amazed me is how this guy managed to win with the crappiest cards and three annoying spirits dancing in his face at the same time.
6. Marik. Dont have too much to say honestly. Guy was the original user of two out of three god cards and used them to great effect. Takes skill.
7. Jack Atlas. I feel he is similar to Kaiba in that he was also quite the character and had some overwhelming power of his own. But his king speeches did get tiring fast. Also he didn't have Kaibas sass.
8. Jaden. I always felt his play was absolute bull. But occasionally he did have a match where he was put into a tough situation and came out with skill. Not ridiculous effects.
9. Akiza. So much potential. So much awesome. All wasted. Reduced to the status of Tea. Essentially useless. Oh well. During the time she was still dueling in the beginning of 5D's she was scary strong, ruthless and skilled.
10. Yuma. Not really sure who to put. Had thought Joey but altough he improved significantly he still played like an idiot troughout the series. Now Yuma is different. Going from being defeated by the equivalent of Cyrus at the start of the series to being a very skilled duelist and does not need Astral really.
Yeah me thinks that fits.