Not sure what 10g is. Here in the States we use letters to size boobs. A through D
A's are lemon or apple sized
B's are Orange or grapefruit sized
C's are cantalope sized
D's are... ok, I've run out of fruits so going to say volleyball sized.
Normally I like smaller boob sizes, the A's or B's. Mainly though I just want the boobs to look good, to look like they are proportional, natrual for the girl's frame.