In terms of male actors, I'm a fan of: Hugh Laurie, Johnny Depp, Toby McGuire, Jake Gyllenhal, Keanu Reeves, Ewan McGregor, Sean Bean, James Stewart, Hugh Grant, Errol Flynn and Harrison Ford. Off the top of my head.
Some may need explaining slightly. Hugh Grant for example, is not massively versatile, but I think he does what he does very well. Ewan McGregor on the other hand is someone I have come to admire in recent years simply for the range of parts he is able to play. The same is true with Johnny Depp.
Harrison Ford, Errol Flynn and Sean Bean seem to have been idols of mine for as long as I can remember, simply because they get given the roles of heroes. Proper men's men. There's probably a gay joke somewhere in there but I know what I mean.
James Stewart was someone originally introduced to me by my Dad, and someone who I orginally disregarded because his films are old and a lot are in black and white. When I grew up though, I realised that he is in actual fact a stunning actor. Certainly up there as one of the greatest ever in my mind.
I find it harder to objectify female actors purely on thier acting skills, for obvious reasons. And perhaps because I don't think women have been able to land as many high profile roles as men. However, some whose talent I have admired down the years include: Olivia De Haviland, Audrey Hepburn, Natalie Portman, Julia Roberts and Virginia McKenna.