I have 8 neons in a 55 gallon tank, and they have been doing extremely well. I would recommend a pair or a trio of dwarf gouramies. 2 or 3 black skirt tetras would do well, if you like black, anyway. Guppies are another good choice for tankmates. You could also try rummynose tetras. If none of these are appealing to you, go to a library and get a book on aquarium fish species. That's what I did. Hope this helps!