Samuel L. Jackson is the best example. He's a more than competent actor (and a cult icon superstar to boot), but he's been in a TON of bad movies because he claims that acting is work and should be like any other profession, any other 9-5 job. So unlike most actors, he doesn't sit around at home waiting for the perfect script (a la two of my favorites, Daniel Day Lewis and Kevin Kline), he just acts and acts and acts. Something of a refreshing attitude, actually.