-Lemons: Lemon cichlids? Or lemon tetras? A small school (6 or so) lemon tetras would do fine in a 10g.
-Lepornius: Needs a much larger tank.
-Mainganos: Too big for a 10g.
Congos: These are pretty big tetras. I would say a 48" tank minimum.
Cardinals: A school of these would be great
Emperors: They get fairly large for a tetra but aren't very active, so a small group might be possible.
Angelfish: Too big for a 10g.
Cherries: Good choice. Get a ratio of 1 male to 2 females. 2 males and 4 females would be even better, as you'd get to see the competitive behavior between the males. The males look fantastic when there are females around to show off to.
Tigers: You'd need a longer tank and a large school of these. I would say no in a 10g.
Ram: You could probably put a breeding pair in there, but nothing else. A single one might be fine with a couple of other small fish.
Apisto: Same as the ram.
Pencil fish: There are pencil fish that would work well in a 10g, but they can be fairly expensive and difficult to find.
How about: 6 harlequin rasboras or similar sized schooling fish like neons, cardinals, black neons or ember flame tetras, 6 pygmy corydoras, and a single betta, dwarf cichlid, or smaller gourami as a centerpiece fish?