Definitely a betta fish. Males can be bought at Wal-Mart for less than 4 bucks. All you need is a fishbowl, some water conditioner, and some food. You don't even need gravel, although it does make the bowl look more attractive. Bettas are smart fish and great little companions, my favorite of all fish. They don't need a bubbler or a filter, so things aren't complicated. A great betta site for care and other info is
www.bettatalk.com. Check it out!