Mainstream credits: Jack & Jill (1999-2001), National Lampoon's Pledge This! (2006)
Adult credits: Young, Hard & Solo II (1993), Young, Hard & Solo III (1993)
Circumstance: Adult film star turned mainstream actor
Rex has been many things—MTV VJ, rapper, actor, Paris Hilton associate—but his first taste of showbiz was three solo films aimed at a gay market. Yep, just a 19-year-old dude fapping for cash. The videos don't seem to have hindered his career in the least; to date, he's made a couple dozen films and had roles on several legit TV series.