betta
two female bettas given a lot of hiding spaces and the right personalities.
galaxy rasporas
you might be able to squish 5 ember tetras in there, you will not make other members of this forum happy though if you overstock like that though lol
cherry shrimp
ghost shrimp
one bamboo shriimp and be sure to put the tank near a window so it can develope the right micro organisms for it to feed on, also, give it a perch of some sort so it can sit up in the filter's current and filter particles.
Snails! oh i almost forgot about snails! there are nerite snails that come in olive, tiretrack, zebra, as well as horned varieties. there are yellow rabbits if you can find them. you can have a colony of malaysian trumpet snails and the get an assassin snail or two to hunt them. and there are apple snails, but i don't like those... they are messy, constantly pooping.
you could get an african dwarf frog or three.
you could get white cloud minnows and then you wouldn't need a heater. there are a couple of varieties, one is prettier than the other in my opinion so you might want to look into that.
here, here is a link to a page on another forum that has fish for nano tanks listed. not sure how easily you can get all of them but it might be worth it to give you the link anyway.
http://www.plantedtank.net/forums/planted-nano-tanks/31095-nanofish-list-v1-0-a.html
have fun.
