Hmmmmmmmmmmmm, this is a tough decision. I suppose my all time favorite is, believe it or not, Niger Triggers. I have had two and I love the way the edges of their fins iridesce when they are all spread out, also lots of personality but not as aggressive as other triggers. Sadly I cannot have another until I get rid of the gigantic mean evil crab from hell that has killed the other two. The other fish never get bothered by it, I think the triggers would get spooked by it and wedge themselves into the rock, making themselves easy pickings for the crab, the other fish just swim away from it. However, I like the crab, talk about personality, this guy has it! This is a FOWLR tank BTW.
As for the fish that are actually alive (LOL) I LOVE my four Azure Damsels. They are absolutely gorgeous small fish that tend to school in the tank and dart about quickly. They are also not nearly as aggressive as other damsels; in fact they leave everything alone, including each other for the most part.
I tend to like a reef tank stocked with lots of small, colorful, and active fish than a few larger fish.