Claim to fame: Most people know her best as Lost's pregnant crash survivor Claire Littleton, while Twi-hards know her from Robert Pattinson's Remember Me. The blonde cutie's real fans, though, know her from as far back as The WB series Roswell. She played the sexy alien-human hybrid Tess Harding, whom we wrote tons of fan-fiction about before we forayed into (clearly) hard-hitting journalism.