What To Wear On My Boyfriend's Birthday Night Out?

Hiya, it was my boyfriend's bday this Friday. Had a relaxed but fun night out last night, just the two of us. Today's the big party day though, as were planning to celebrate with friends and hit the best bars in town! So what am I gonna wear?! It's very hard to decide or even cut down the choices because I DON'T KNOW what kind of places are we gonna end up to. So maybe I should just stick to something kind of basic that I could wear anywhere? Not too fancy but not too dressed down. I think I still need some inspiration though...