I'll admit it, I'm a sucker for big bluegill and have dedicated a lot of time and resource in pursuit of them. I dont really know why, but I sure do!
I found the big bluegill get plenty piscivorous in the right setting. Once the spawns have started I hit em with small, olive/gold/flash baitfish patterns and do really well. I have found they will attack much larger prey than you would expect, and the key is having a hook small enough to fit in their mouth. I've had them eat a miyawaki popper before, and gotten the hook too.
I haven't found much they wont eat. The challenge is finding the right bug that keeps the small ones off but still attracts the big boys.
Love the foam triangle bluegill bugs, hook slides right in but they cant swallow it.
Also, returning your large male catches is the best way to increase average size of bluegill in your pond/lake. The big males are the dominant breeders and will keep the smaller males from making nests. This keeps the smaller males from reaching sexual maturity (and the drop in growth rate associated with it) as well as keep the total number of fry lower helping stave off the stunted populations we so often see.
Get those gills!