Brad Pitt is a really good actor,even though he is a stuck up prettyboy in his personal life. That still does not negate the fact that he is a very diverse actor and can play almost any role given to him.I can't believe nobody has mentioned him.
I cannot say I have a favorite actor as there are plenty of really top notch actors out there now. Such as Travolta,Cage,Carrey(hes friggin hilarious and should stop trying to be dramatic as nobody wants to see him in that vein),Samuel L Jackson,Deniro and many others I forgot and don't have time to list.
There are also some that I think are way overrated,such as Matt Damon and his bunbuddy Ben Ahfhuck.
SNL spews a ton of great comedians too. Without that show I wonder how good our comedies would be.
I love to watch good movies and bad acting sucks,especially when you pay 8 bucks to see it.