Most places I've lived, including here in MS where they get big, an 8 inch bluegill is a good one and bluegill between 8 and 9 inches are somewhat common. Above 9 inches long is rare enough to be somewhat of a trophy around here. I don't fish often and so 10 inches or larger bluegill are very rare to me, although I will generally catch a few shellcrackers longer than that each year.