Depends on where you live. Some places have restrictions on certain types of ammo.
I think just having JHP (Jacket hollow points) is good enough. You can pay top dollar but you'll probably only get marginal improvement.
That said, because I'm a hypocrite, I use Federal Hydra-Shoks. However, I think you'll have many Golden Speer fans here and it is actually recommended by the local range owner as well.
"For every problem there is always a solution that is simple, obvious, and wrong." - Mark Twain