Unrealistic character: Adam Jensen (Deus Ex)
Realistic character: Tingle (Zelda) or Andy (Advance Wars). Can't decide between the two.
Andy because I want to dual wield some wrenches. A wrench to the face would be painful and fun to watch
Tingle because he has moveset potential. He recently started his own spin-off series. And he is a better rep than Ghiriam in my opinion.
As for Adam Jensen, he comes from my second favourite game of all time (first being Windwaker). He has moveset potential, like he can blow everything up in his near vicinity. He has super strength (to the point where he can break walls) and he can turn invisible. Plus there are a lot of weapons he uses, including a taser.
If you haven't played DeusEx: Human Revolution, get the Directors Cut on WiiU or Xbox or PS3