[MattS]

Kevin Kline
Claire Danes
John Cusack
Sigourney Weaver
Bill Murray

These are some actors who were not mentioned in this thread yet. Although I can not claim to have watched all movies they have made and although they probably have made bad movies in other people's eyes I enjoyed all their performences in the ones I have actually seen.

This is also true for Matt Damon, Tobey Maguire and Kevin Spacey. But those were already mentioned above.