Honestly it sounds like a horrible problem to have. Here are the ones that spring to mind, though...

Leonardo DiCaprio
Tom Hanks
Tom Cruise
Brad Pitt
Cameron Diaz
Morgan Freeman
Ralph Fiennes
Nicole Kidman
Michael Caine
Maggie Smith

In time, probably Jennifer Lawrence. But yeah, opting for older people because of the volume of films I know I like by them.

Reeeeeeeeeeeeaally tricky to pick just one, though. I'm... urgh, no, I can't do it.