Doesn't matter as long as they are in proportion with rest of the body. Its not a deal breaker for me anyway as I am a legs and bum type guy.
I must say I've always been self conscious about my relatively smaller breasts, and some of the responses here are reinforcing those feelings. Let me just say while they are not huge, they are big enough so that when a guy places his penis between them, i can squeeze them together enough to make him explode on my face.
I do love watching big boobs bounce around s makes my Dick instantly hard but I do love smaller boobs too
Sagging breasts don't necessarily look bad. I've heard that some cultures actually prefer the appeal of sagging breasts as opposed to perky ones. I don't recall which ones, just hearsay.
Don't have a preference and really like all sizes. Firm or saggy and yes saggy can be quite sexy, as well. Always like seeing them hanging freely.
I absolutely love big natural tits. Fake tits don't do it for me. I like the way they hang the way they bounce. Big natural tits is my favorite search when watching porn.