I like a nice perky C or D, but honestly it depends on the girl's build. If she's very petite I don't mind something smaller and if she's more of a plus size I prefer bigger, I guess for me it all comes down to keeping things proportional.
For some reason, almost every girl I've ever dated has been a 36C so that's kind of become my favorite size. It's to the point where, once I date a girl long enough that we start getting naked and I ask her what size they are and she says 36C, my response is "Of course they are."
