Betta, get the ones bred for fighting. Now those are some real monsters for their size, sheer power, agility, and aggressiveness. Might be a bit expensive, but I can hook you up finding the good ones for $45-50.00, or you can go to Mr Precha. He might be able to cut some prices off for you, he's an online betta whole salesman from thailand. Very trustworthy, probably the most trustable guy. But the more you buy the less it cost.
Other than that, uhhhhh...guppies?
Other than that, uhhhhh...guppies?
