The Big Bang Theory: 10 Best Characters Who Appeared After Season 1

10. Priya Koothrappali

While Raj’s character can sometimes be boiled down to a stereotype, he’s given greater depth whenever the show dives into his family life. The brief addition of his sister Priya helped to ground his character, and in her 12 episode arc on the show she’s given some solid development of her own.

Priya is presented as one of the few viable rivals to Penny for Leonard’s affection, being presented for the most part as a great match for the scientist. She’s a hugely successful lawyer, well travelled and cultured and more than a match for the highly functioning gang - most memorably when she uses her legal skills to tear apart Sheldon and Leonard’s roommate agreement over the course of an episode.

In a show that often skews towards the cartoonish, she’s one of its most believable characters, charmed by her then-boyfriend Leonard’s quirkiness to a point, but eventually becoming exasperated by his behaviour.