I've said it before, and I'll say it again, Diablo 2 is NOT an RPG. It is an action-RPG (which despite the name has allmost nothing to do with RPG's)
But isn't a 3rd person game where you only control one person called an RPG. Even though it may not have a lot of talking situations to make it boring, it is still an RPG. Even if it is an action
RPG, it is still an RPG. You kill things and pick up items to trade or sell.