I think the key is that the character either has to be
A: Relatable
B: Silent
C: Obvious Parody
This is why i have more favor for characters like Samus, Link, and Mario, or from a non-Nintendo universe, Master Chief, because they either remain perfectly silent, or they at least don't muddy up the story with their personality, imposing their personality on the theme of the game. Then there are obvious parody characters like MadWorld's Jack "Ex-Marine, Ex-Navy SEALS, with a chainsaw grafted to his arm," or Duke Nukem. and finally characters who are relatable, which generally comes down to them having some sort of emotional weakness without being overly emotional. Like Famousringo said, Travis Touchdown is a good example. Ike from Fire Emblem is another, just a regular guy who happens to associate with the highest of circles (as far up as associating with the divine). Certainly implausable, but at least it's relatable
Basically what a lot of games do today is to take what was an obvious parody, Duke Nukem, and try to make him into a serious character, and you get what you see in a lot of games (notably Gears)
Monster Hunter: pissing me off since 2010.
