I have a community of two female bettas. They are really active and fun to watch if you get a group of them. I also have a common goldfish. I don't like the deformed ones. Of course a 10 gallon is much too small for a goldfish.
Lyretail mollies, especially a true yellow, are exotic looking yet small and easy to take care of. You can find so many colours. This one is a pineapple colour.