seeing your other tropical tank...i would get a small school of corys. Around six. A bristle-nose plecostomus and maybe some livebearers(patys, mollies, swordtails, guppies) or what would look really good in that tankw ould be some rainbows. I think thier called boseman. But they are really pretty!
It depends what kind of fish you're into really...but I would put a flock of something pretty, like harlequin rasboras or threadfin rainbows or sparkling gouramis, and either a few cories or a few otos.