If you're ok with a species only tank, Tiger Barbs have very interactive personalities. They're entertaining and not shy at all, and they come in several different colors. The only problem is that they are aggressive, so they do best with their own kind only. People have mixed experiences with these fish. I personally liked them, even though I ultimately decided to stop keeping them. When I purchased a school of about 10 babies and raised them together, I didn't have many problems other than the usual chasing and stealing food (they will steal food right out of another Tiger Barb's mouth). However I had a disease wipe out all but one and when I tried to restock the tank, I ended up with serious aggression problems. So if you do go with Tiger Barbs, I would say your best bet is to raise them together as babies.