All right, all right.
3D really named off some good ones (especially Morgan Freeman in Shawshank!), so I put my thinking cap on and came up with these guys:
Tom Hanks in Lost. I have never been so captivated by one man on a screen, alone, for so long. I think that's an underrated performance. Truly great.
Speaking of Tom Hanks, let's try Forrest Gump. Funny, poignant, and always interesting. I could watch that movie over and over and over.
For "cool" there's Preacher from Pale Rider, and for just plain awesome there's William Munny from Unforgiven, to name a couple of Clint Eastwood characters. One more by Eastwood is Frank Horrigan in In the Line of Fire. I just feel comfortable with Eastwood on screen.
I'll come up with some more later. Like I said - there's tons.