All tetras such as;
neon, black neon, black skirt, red eye, red serpae, emperor, bleeding heart, head and tail light, congo, and a few more ~ 6+
silver dollars 5+
australian rainbowfish 5+
danios (many kinds) 5+
barbs (some can be aggressive such as tiger) 6+
there are many more schooling fish, these are just some common ones. Make sure you don't overcrowd your tank, Good Luck
Zebra and golden Danios. About 25 of them.