Mainstream credits: Batman TV series (1966-68)
Adult credits: The Happy Hooker Goes Hollywood (1980), Young Lady Chatterley II (1985)
Circumstance: Mainstream actor with some racy mid-career credits
Adam West was and will always be the campy TV Batman of the '60s, but a decade after the series ended he was a man without a mission. Why not act in some "non-sex" roles in tasteful Cinemax Friday After Dark fare? His films were extremely tame in comparison to others on this list, but come on—it's Adam West. The creepy voice of Batman interrupts your enjoyment of gratuitous nudity, causing your head to explode.
In today's Age of Irony, of course, Adam West is in high demand, and that creepy voice has earned him cameos in Funny or Die skits and a recurring role on Family Guy.