Chili rasboras are pretty. Make sure that you get brigittae (with the stripe) rather than merah (with the square or diamond) because brigittae turn a beautiful red once they've settled in.
Another fish to consider are aphyosemion killifish. These fish enjoy small tanks and spawn easily. I have some aphyosemion primigenium 88-10, which are apparently extinct in the wild and hobbyists keep their particular line going.
If you want some aphyosemion primigenium I can give you some of my nearly-grown fry. A 5 gallon tank can take two spawning pairs, according to Graham at Noah's Pet Ark. These fish are quite slow-moving most of the time, spending a lot of time staring out the front of the tank, and they love a very heavily planted tank. They're very different from chili rasboras, which I also have, as chili rasboras dart around in their little school, enjoying a lot of movement. But aphyosemion are known to jump, so their tank must be covered.