4. Stuart Bloom (Kevin Sussman)
"What would you recommend as a present for a 13-year old boy?" "Um, a 13-year old girl?" Initially in a supporting role as the cash-strapped comic book store owner with a strange crush on Penny... or any woman, really, he's not particularly fussy Stuart's screen time has grown in the latter two seasons of the show and he fills in the role of 'unmarried friend' for a still-single Raj by time Howard marries Bernadette. The whole gang even consider him as a potential replacement for Howard once he's away working at the International Space Station. Stuart's character is so deeply miserable and depressed, with his life seemingly in tatters, that his continued presence on the show somehow makes the other character's look somehow cool. And that really is no easy feat.