LOL. I tried doing this, but couldn't come up with a single actor or actress, unless they're new or have only done one movie & it was a hit. but established, great actors... couldn't find a single one. almost every single one of them had a flop or a movie I hated somewhere... usually in their early career. look at my love Leo DiCaprio, he's an amazing actor, but he had some craaaapy movies his early days.
now, there are some actors that to me that have never made a bad movie, because I haven't seen all of their movies. Ben Affleck. Matt Damon as well... except I HATED The Good Shepherd, even if it went over well. Mark Wahlberg... if I hadn't just seen The Happening, and haven't seen his early movies. oh, Joaquin Pheonix, but again I haven't seen his early movies.
actresses, Reese Witherspoon. but I haven't seen her early movies.
oh, Morgan Freeman! but AGAIN, haven't seen quite a few. I could probably name ten here, that I think have never made a bad movie because I haven't seen them all, and I'm not just going on what the critics said... critics can be completely opposite of my opinions.
so basically, I won't be able to come up with a single one... they've all either had a bad movie, or I haven't seen all of their movies.