I find a few actors very underrated. The first is :
Jim Carrey- I saw him in a dramatic role about 15 years ago and he was awesome. I thought it was going to be his breakout role. He has stuck with goofy and that's a bit disappointing.
Brandon Frazer- Very good actor who has gotten pidgeonholed with the mummy movies. He can act when the script calls for it.
The older brother in the show supernatural.-I love the show and he makes the show. It would not work without him.
Haden Christianson- Just kidding, this kid truly sucks.
Add to my list??