Regular ramshorn. As long as the tank isn't too small. I had a bunch of pink ramshorns and some BV's in a 1 gallon on my nightstand. A few of the shrimp had trouble molting and the snails got them. I have since reduced the number of snails and now everyone is fine. The snails do a great job with the algae and don't do any noticeable damage to my plants. I have started spreading out the pink and leopard ramshorns to my other tanks.
Got tired of the nerite eggs and the clumsy things kept falling over on their backs and dying if I didn't get to them and flip them soon enough. I have lost all of my tracked and zebra nerites, and half of my olives too. The only ones that seem to be able to right themselves again are the little horned nerites.
But IMO, the ramshorns do nearly as good of a job with algae control and I don't mind that they breed quickly. Their eggs are little clear clusters and don't look as bad as the nerite eggs. I recommend mixing a little crushed coral in with your substrate. The ramshorns' shells can look kind of crusty if they don't get enough calcium, but the few that have been raised in my sand and coral tanks are beautiful. Check this one out.
