If you are looking for a strikingly colorful and active fish to brighten up the tank with, then watch out for these guys. Half the time, they look like they're on drugs, they've got so much energy! They tirelessly swim to and fro all over the tank, and usually amuse themselves by following one another.
The wild type rosy barb is already pretty colorful, being a silvery pink to maroon shade on the bellies of the males with black tipping on the fins, but now they have bred outrageous neon and long-finned varieties that are amazing. The long-finned barbs do tend to run their own fins ragged with all the fast swimming they do. They must be given open spaces in which to swim, I recommend at least 20 gallons, though they can get by for a while in a 10 gallon. They're very greedy eaters (prefer meaty foods, but do well with variety, not picky) that snatch up food,
so make sure you have fish that can compete.
Also, their constant motion disturbs some very shy or slow fish, and occasionally they have been known to nip a long trailing fin, though this is not as much a problem as with the tiger barb.
The nice thing about these fish is that they are not only beautiful, but quite hardy as well. In my parents' 54gal tank, they were at one point the only fish to survive a filter disaster (my parents cleaned out the filter too well after a move, and all the good bacteria died off, forcing the new tank to cycle again).