Generally getting a critter to take care of algae isn't the best idea. They're generally ineffective or too large for the tank. That being said, Olive Nerite Snails may be the best bet. I'd skip on Otos as there is a lot of algae they won't touch, and they should be kept in schools.
^^Hehe. Yeah, I wouldn't suggest Otos in a 10g, because they like to shoal, so you really need 3+ for them to be happy. Thats a bit much for a 10g when you have other fish in the tank.
I'd suggest snails, or finding the type of algae you have and fixing the problem. If you don't have algae yet, remember, you don't need an algae eater in every tank.