Penny is simultaneously one of the most laidback and easily offended people you'll ever meet. On one hand, if you don't press any of her buttons, she'll be endlessly chill and easy to get along with. She'll hang out all day, kick back beers and play video games, and carry on with the rest of them. But if you dare approach feminism or any of her other activist causes with a negative attitude, she won't hesitate to school you. And being the sort of person who is so invested in her causes, she absolutely refuses to be friends with people who are sexist, racist, or anything similar. Even if just the slightest bit. In that sense she's quite the grudge holder.
She's also a hardcore atheist and doesn't hesitate to express that regularly. She's constantly making Jesus jokes and rolling her eyes anytime someone mentions God. She's not the sort of person who will snap back at a person for saying "God Bless" or "Merry Christmas," mind you, as she quite loves fictional baby Jesus at Christmastime because he's so goddamn cute. But she's also not the type who will censor herself around religious people, and she also doesn't believe religion does much good in the world. Perhaps she comes across as cynical, which is not entirely untrue.
In fact, while love is cute and fun and maybe desirable, she's not entirely sure she believes in it. She certainly doesn't believe in men easily, and considering she's heterosexual, she feels like her chances at finding love are slim to none. She's dated in the past, but it's always crumbled apart with ease whenever a man betrays any sign of sexism. (She can forgive accidents... for the most part.) She's also the sort of girl who will spin right on her heel when a man is catcalling her, as she seems to have no regard for safety. One of these days she'll get herself into trouble.
Penny also tends to be cynical about the world, particularly the government. She's not too happy with the way things are, and while she's not a conspiracy theorist, she doesn't hesitate to throw out that "oligarchy" term when discussing the United States. She's extremely liberal and doesn't tolerate much conservatism without heavy eyerolling and fierce arguments. She trusts few government officials and could even get herself into trouble with them, considering how much she'll talk back.
Needless to say, she's as bit of a forceful, opinionated personality. But don't let that fool you-- she's incredibly kind, compassionate, and goofy when you don't press her buttons. To most she comes across as pleasant and laid back, in fact, as she doesn't get offended by much when it's directed at her. She can joke around and dance like an idiot, and people often love her outgoing personality when going out, as she just doesn't give a shit what other people think. She's a funny girl.