Mario and I have our disagreements :P , but overall his games and adventures are awesome and great for playing with friends. For example, he's totally awesome in Super Mario Galaxy, and kicks but in New Super Mario Bros. Wii.
Not to sound trite, but there are a lot of characters I've loved. Link, Auron, Kratos, Samus and many more. If I had to choose, though, I guess I would say Ghaleon from Lunar: Silver Star and Lunar: Eternal Blue. Perhaps it was because of my age when I played it, but the character (and overall game) made an impression and it was the first time, that I can remember, that a character was in an original game and a story driven sequel.
Well, it's hard to choose but I'd say Crash Bandicoot. He's pretty wacky and a classic video game character. Its been a long time since I've played any of his games though.
I'd say Cole Mcgraff from inFamous 1 and 2. Mainly because he had to go through a lot of betrayals and one was from his best friend. His powers were wickedly cool to use and look at and gave me a reason to play in the dark. Plus he can climb faster than Ezio or Altair from Assassins's Creed.
Amaterasu from Okami all the way!!! How often do you get to play as a wolf? (LOZ twilight princess doesn't count) Also you can literally paint symbols to affect the environment around you (or kick butt). Plus he looks awesome in his japanese painted being.
For me, it's a tie between Luigi (Mario series), Proto Man (Mega Man series), Ryu (Street Fighter series), and Akuma (Also from Street Fighter).
Luigi is the brother of the world famous plumber, Mario, but he jumps HIGHER than him, which is basically Mario's most distinguishing feature.
Proto Man is just kewl sauce. He's so kewl he wears sunglasses UNDER his helmet's sunglasses. Having his theme song play WHENEVER he enters an area is kewl too. (Yes, I know how to spell "cool"
About Ryu. HADOUKEN. SHORYOUKEN. Period.
Akuma beats your face in mercilessly and poses over your dead body. Also kewl sauce.
Jansen Friedh from "Lost Odyssey".He is so awesome. And also Alistair from "Dragon Age Origins". I guess I do kinda like these cynical weirdos in videogames.