Nerites are certainly the best snail to buy if you've got an algae problem.
1. They're absolutely adorable
2. They don't breed in freshwater
3. They're non-aggressive
4. 5 Nerites in a 10 gallon tank coated with algae will clean it up in about a week
5. Nerites are just....too....flippin....cute.....(you should see their teeny lil faces! And their eye stalks? FREAKING ADORABLE)
6. Nerites may poo a bit but not so much as to really pollute the tank
7. Nerites will nom the algae off plants but not eat the plants themselves (though sometimes they can't resist a nibble of water sprite or anacharis, but give them a break....they do so much for you, they deserve a treat ;)
AWWWWW YEEEEAAAAAH anyway just get a Nerite snail. I don't know, but I have a good feeling about them. They're just too awesome to describe. I almost love them more than bettas :O