Just to clarify, hermaphroditic does not equal self-fertilizing. Some snails are both, but they are not synonymous. There's also different types of hermaphroditism (sequential & simultaneous). The nonself- fertilizing snails need another snail to breed with in order to reproduce.
When it comes to the most common aquarium snails:
Physidae (bladder/pond snails) - Hermaphroditic and self-fertilizing
Planorbidae (ram's horn) - Hermaphroditic but need an another snail to mate
Bellamya chinensis (trapdoor) - gonochoristic
Ampullaridae (Applesnail & giant ram's horn) - gonochoristic
Tylomelania sp. (rabbitsnail)- gonochoristic
Clea helena (assasin)- gonochoristic
Melanoides tuberculata (Malaysian Trumpet)- gonochoristic, but females are also parthenogenic
Neritina (nerites)- gonochoristic (I'm fairly certain... oddly not many papers on this, at least not open access)
