Who are the sex symbols of science fiction?

Whom would you personally consider to be the most physically attractive men and women of science fiction, past and present, both on film and television? (Note that to qualify they have to be associated with sci-fi; Pamela Anderson for example may have appeared in Barb Wire, but she’s not really known for that.)

Nichelle Nichols? Katie Sackhoff? Claudia Christian? Jeri Ryan? Catherine Schell? Amanda Tapping? Carrie Fisher?

Leonard Nimoy? Patrick Stewart? Scott Bakula? Harrison Ford? Buster Crabbe? Hugh Jackman? Chiwetel Ejiofor?

Someone else?