A lot of the species are commonly available in the aquarium trade are not suitable for a 10g tank, but there are still some really awesome ones out that are very rewarding to keep, but you may have to order them online.
A few to consider are dwarf puffers, ember tetras, shell dwelling cichlids (specifically look at L. multifasciatus), clown killifish, Norman's Lampeye killifish, neons, green neons, bettas (there are more species than just the Betta splendens you always see in cups), dwarf gourami, croaking gourami, sparkling gourami, scarlet badis, pygmy cories (C. pygmaeus, habrosus, hastatus), Asian stone catfish, otos, jellybean tetras, chili rasboras, celestial pearl danios, gold ring danios, micro rasbora (like emerald and dwarf spot rasbora to name a couple), guppies, platies, Endler's livebearers, least killifish, and pygmy sunfish. There are more too, but those are the ones that pop to mind. Keep in mind that not all of these fish are compatible and some have very different needs, so I suggest researching them to see if you are interested in any.