Mosquito Rasbora (Boraras brigittae) is a good fish for a 10 gal. If you add some live plants they will do rather well. They should be kept in groups of 6 or more because they are a schooling fish.
Definitely not for a new tank, though - my experience of them is that they are fairly fragile. :( They are beautiful fish, though.
Originally Posted by MaisyDawgThirteen
Actually, do NOT get only males. I just learned the hard way. :[ Get 2 or 3 females and 1 male.
Three male Endler's would work. Even prettier than guppies, IMHO. :)