8. Barry Kripke
A lot of Big Bang Theory’s supporting roles can be boiled down to a pretty basic joke, but the show was smart in casting accomplished comic actors. In other hands, Barry Kripke could be somewhat distasteful - the majority of the humour comes at the expense of his speech impediment.
The versatile John Ross Bowie breathes so much malevolent life into the role, though, that he turns Kripke into somewhat of a supervillain, the self aware nemesis to Sheldon’s uber confident hero.
In classic sitcom style he’d pop up once or twice a season, usually to do battle with Sheldon. The two would have an inept basketball standoff; Kripke utilised helium to ruin a radio interview; they’d snipe professionally and exchange barbs, with Kripke unpleasant enough to make Sheldon look like the good guy.
He’s a slimy sitcom letch in the classic sense, but played with such verve and mischief that he works as a character.