I like big boobs, but there are certainly limits. The first pic in this thread of Angela Devi does show fantastic tits. Although Angela Devi (R.I.P.) had a petite figure her tits were -in my eyes- big but not too big and a perfect match with the rest of her body.
The second pic in this thread, the one of Chelsea Charms, shows an act that belongs in a circus or freak show.
A cup DD(D) (plastic or not) is perfect in my eyes. Although there are exceptions. E.g. I love the boobs of Busty Angelique (EE) and nubian pornstar Sierra (F).