Personally I love the depth of the game. There's over 110 different champions to play as, and they are all very different both flavorfully and mechanically from one another, and they all interact with each other in different ways. It's fun to find a champion you really enjoy playing like Elise the Spider Queen, and then mastering her. Talking to other players, you can tell them "Oh yeah, I'm an Elise Person" and that means something.