Bernadette, played by Melissa Rauch, is a Cheesecake factory waitress that works alongside Penny.  Penny introduced her to Wolowitz and now the two are dating.

She's actually quite smart and is working her way through graduate school microbiology studies.

Bernadette Quotes

I'm the kind of girl who can get all the giant missiles she wants.

Bernadette

Penny: He wasn't intellectually stimulating enough.
Bernadette: Couldn't you just fool around with him and then listen to NPR?
Penny: Wouldn't help. Zack couldn't even spell NPR.

TBBT Quotes

Raj: Okay, here's another one: if a zombie bites a vampire, and the vampire bites a human, does the human become a vampire or a zombie? Or, a zompire?

Amy: Sheldon, there's something else I've been wanting to say, but before I do, I just... I want you to know that you don't have to say it back.I know you're not ready, and I don't want you to say it just because social convention dictates...
Sheldon: I love you, too.
Amy: You said it.
Sheldon: There's no denying I have feelings for you that can't be explained in any other way. I briefly considered that I had a brain parasite. But that seems even more far-fetched. The only conclusion was love.