WoW is far from Diablo online, but its pretty mainstream, though what makes it stick out is the instances (think of it a copy of a dungeon just for you and your party) and quests, seriously you don't have to grind in WoW, not even for money (well a bit), even the devs said that most of your equipment will be drops and rewards not ones you bought off the Auction House or bought it from an npc vendor.

They are right, i'm a 48 orc warrior and 90% of my equipment are rewards from quests and drops.