Any fish are the best, I prefer tangs and butterflies. I even like damsels, but they are mean little devils. My clowns attack me when I clean the tank, so I caught him in a cup. I left him in there till I was done, scared the crap out of him. But I bet he will attack me again the next time I clean the tank.
Best advice is go one way or another. Peaceful or agressive. That makes buying food much easier and cheaper when all your fish eat the same thing.
Agressive, get less fish since most agressive fish eat more and are messy eaters. This will keep your water clean.
Peaceful fish are cool because you have more variety, and down the line you can go reef if all the fish are reef safe.
In my 125 I have only one fish that could be called "Agressive" and thats my picasso trigger. And he is the chillest fish of them all.