Ezio Auditore started off in Assasin's Creed 2 as a Spoiled Brat and by the end of the game he graduated to a Giant Douchbag. The following games in the series he wasn't much better, they just replaced his dumbass/ arrogant personality with an even more boring one. I will Remember his AC games for the story and the great gameplay, but not for his character. Thank god AC3 has a new main character.
Solid Snake always reminded me of Snake Plisken. He's the Ultimate Cool-as-a-Cucumber Badass.
Tommy Vercetti was a stereotype, of a sterotype, of a mafioso gangsta. Boring, and nothing new or original, I would say his personality was like his appearance flashy on the outside/ dull and lifeless on the inside. Not the highlight of Vice City.
CJ was a young black gangsta stereotype, but at least he was a bit more original than Tommy. He was the first playable black protaganist in a GTA game, and a major reason not to like San Andreas for many uptight closet-racist gamers. That just gave me another reason to like it, and to be impressed with Rockstar for trying different things. Things that might be unpopular with a mass audience. Rap is not very popular in society, at least not proper rap. And this game helped spark a bit more interest in it.
John Marston was an interesting character, even if they tried too hard to make him into a likeable average joe, who just happens to be an expert marksman, and a mass murdering gunslinger ( kind of the same thing with Nathan Drake ). For once I would like them to make a truly unlikeable anti-hero.
Niko was an almost perfect character. Truly original ( haven't seen anything like him in other games ), he was not perfect ( far from it ), and very human in the mistakes he had made in his past. He was likeable and un-likeable at the same time, and had an interesting personality and backstory to boot. If Rockstar can continue to make characters that are as original as he was, I will be very happy. Can't wait to see what they come up with