1. Kamina (Tengen Toppa Gurren Lagann)
While Simon's character arc is much more interesting and overall more grand when it all comes together I have to pick Kamina. It's like he's the embodiment of all the inspiration of this show rolled into one character. Then through his personality it emanates onto all the other characters.
2. Xellos (Slayers NEXT and onward)
Introducing himself as the "trickster priest" he is one enjoyable character. Not only does he have enough power to vanquish almost whoever he wants, and manipulates Lina and co. he still stays buddy-buddy with them, popping up whenever he pleases.
3. Vash The Stampede (Trigun)
This man is an absolute legend. I just love how he acts and his sheer resolve to never take a life. There are the times where he is hilarious but when **** goes down I can do nothing but take him seriously. Just a really really good protagonist.
4. Eikichi Onizuka (Great Teacher Onizuka)
I seriously wish I had this guy as a teacher growing up. He's in-your-face, he's funny, he's wise, he's perverted, he doesn't take crap from anyone, he can be calm and collected, he can go nuts at the drop of a hat, and he always pulls through in the end even if all odds are against him. He wants to teach people about things that aren't in the curriculum, the things that really matter in life.
5. Lelouch Vi Britannia (Code Geass)
Another amazing protagonist that kept the entire show together. His actions in the end (spoiler) sealed the deal for me. That sort of self-sacrifice in really good stories always gets me. He's very clever and entertaining and I could never fully tell what he was going to do next.
6. Makoto Konno (The Girl Who Leapt Through Time)
It's really hard not to love this character. She acts just like a real person, it's remarkable. She's funny too, I love her crazy laugh about one third in. Plus she looks adorable in every single frame she's in. That's something.
7. Konata Izumi (Lucky Star)
Definitely the most relatable character on my list. An everyday otaku, not much else to be said.
8. L (Death Note)
This character made the show work so well. He was the perfect counter for Light. His intelligence is near in-human and his mannerisms are so entertaining.
9. Gendo Ikari (Neon Genesis Evangelion)
Probably the only character of the series that I like apart from Misato (who should be more appreciated). The whole time watching the series I always had that feeling he had a good reason for being such a cold father to Shinji but I wasn't sure what. When he said in the movie that he was too afraid to get close to his son because he didn't want to hurt him I laughed. Him and Shinji were just like each other and didn't know it.
10. Excalibur (Soul Eater)
Excalibur shows off a blend of comedy I don't see too much of: complete self-involvement. He has untold power to be used by whoever wields him, and yet he's so incredibly annoying and irritating that no being alive can bring themselves to be around him. His few episodes are a riot and his ramblings are both interesting and ridiculous.
Others I wanted to include in this list: Lina Inverse, Llyod Asplund, Tamaki Suoh, Kyon, countless others from Tengen Toppa Gurren Lagann, Fullmetal, and Soul Eater.
From what I've seen of Kaiji, the title character is actually pretty amazing. I may have to edit this later, or leave this mention here.