A 10g can make a very cool nano fish and shrimp tank. I have two larger tanks of nano fish and just to name a few that would work:
Ember tetra's
Celestial Pearl Danios
Chili rasboras (they turn an intense red and are tiny enough to have larger school)
Neon rasboras (blue, green, and gold color varients)
Burmese Rosy Loaches (very active little loaches for bottom activity)
Multi Stripe Pygmy Loaches (also very active little loaches that use bottom/mid levels)
Scarlet Badis
Endler's
Spotted Blue Eyes (very entertaining little fish- males display to each other and females
with extended dorsal fins) *one of my favorite nano fish
Dwarf Anchor cats (for catfish lovers)
Pygmy or Dwarf Cory Cats
You can also do any type of small shrimp with the above fish and also Mexican Orange Dwarf Crayfish that are bight and fun for kids. I have Fire Red Cherry Shrimp that are very bright colored.