In my opinion you can't go wrong with a firefish. I have replied to guite a few posts while singing their praises.
I have a pair of the "red" (magnifica), the cheapest of the three. The purple and heilfrichi (sp?) are beautiful as well. My first one was killed by a more aggressive fish. It would swim around in the open most of the time just kind've hovering in the middle. Never tried to jump, although they are VERY well known for doing so. The pair I have now live in a piece of live rock and spend most of their time in there when a lot of activity is going on in the room. They are shy. They get along well with my yellow tang and mandarin. These have never jumped either that I've seen...lucky me I guess. I had a bad ick breakout over a month ago, and they are the only two fish that survived....they didn't even show ANY signs of being sick. Very hardy fish! They were often visited by my bar goby and my coral beauty, hanging out in the same hole. I miss thouse guys.
Anyway, if you don't have really aggressive fish in the tank, they are great to have. They accept most foods as well, although mine won't venture far from their home to get it. They will only eat what is in their own backyard, so to speak. Flake, marine cuisine, brine shrimp, plankton, etc. I could ramble on forever, but with all these other replies, you get the picture. No negatives on this fish except the jumping, which they may or may not do, and being easily tormented by bullies. Good luck!