schooling fish (neons, danios, etc.) are great, and when put in large groups look BEAUTIFUL in large tanks where they have lots of swimming room.
PLEASE THOUGH:
I read that you put a betta in that tank with those other fish. What many people fail to realize is that bettas are solitary, and prefer to have their own tank. Bettas are not a community fish, nor should they be treated like one. They are beautiful fish but have a tendency to pick on, bully, or kill other fish, whether their own kind or not. You should definately move the betta back to his 10 gallon! You might have a betta with a much calmer temperment than most, but it is always better safe than sorry. Many bettas will not tolerate "tank mates" or "buddies". The only thing I have ever seen work with a betta was a pair of snails. They were great for cleanup in the beginning, but they hid a lot because they were always scared of the betta (he bullied them). And the betta was constantly stressed out with the snails. He kept trying to defend his territory by biting and nipping the snails. It was just a big mess, so I would recommend keeping your betta by itself in the future...