I'm still working out my top ten lists. I have done a little bit of work, though.
1. Robert DeNiro
I can tell you right now that this cat should be on top. Perhaps not the most talented among the bunch (you could say that Brando had more raw sexuality and chops), but definitely the best all around candidate with range and an amazing list of films (by far, the best out of the top 300, imho).
Check these out: Raging Bull, Godfather II, Taxi Driver, Goodfellas, Once Upon a Time in America, Mean Streets, Deer Hunter, and King of Comedy and Casino somewhere in the top 500...
If we needed a tiebreaker between him and Brando (more on him in a sec), check out GF II where I think ONLY he could have pulled off a performance as the young Brando-Corleone.
Influence? Hear it. Strength/quality of individual performances? Okay. The breadth just isn't there though. Sandy Koufax of acting. He's hurt by the fact that he only has two leading roles in Top 100 flicks. He's at best a bit player in Apocalypse, something akin to Welles in Third Man (though not as good as Welles's turn as Harry Lime). Incidentally, the lack of great FILMS to support the great PERFORMANCES is one reason why I've rethought Nicholson and Hoffman. Just not there.
3. Cary Grant
WTF? Why isn't he on our top list...maybe top 5? Talk about no respect! Look at this guy's list from the top 300:
North by Northwest, Notorious, Bringing up Baby, His Girl Friday, Philadelphia Story, Only Angels Have Wings, The Awful Truth, Gunga Din...
We have range and quality in spades.
4. Intriguing also rans (those who won't quite make it but who are analogous to Oldman as best supporting nods...)
a. Joseph Cotton
b. Sterling Hayden
c. Gene Hackman
d. William Holden