[Ham n Cheese]

ITT we post actors who surprised us with good acting, typically not known for it.

Stallone - Cop Land (started well, did lots of mindless action flicks, then reminded us all he had talent)
Adam Sandler - Punch Drunk Love
Jamie Foxx - Ray (showed signs in Ali)
John Travolta - Pulp Fiction
Keanu Reeves - Speed (awesomely bad movie, not a great performance, but when I heard it was Ted Logan playing the lead I never expected this)
Jim Carrey - Eternal Sunshine (not his first serious role, but I thought he was amazing in this, much credit to Charlie Kaufman though)
Ben Affleck - Hollywoodland (I thought he was really good, sort of a redeeming role after starting well, going to the shitter, etc - too bad his career as an actor is pretty much dead now)
Tom Cruise - Vanilla Sky (showed talent in many movies in the past, but was blown away by this movie, which is essentially just people talking most of the time, really have to credit the acting in roles like that).
Sean Penn - Dead Man Walking (Spicoli!)