What are some good RPG games for the Mac?

Just got a mac and I’ve got 50 dollars to spend, looking to buy myself an RPG. In the past I’ve enjoyed WoW and Dungeon Siege. Ideally I’d like it to be a single player, non-online game with a high amount of re playability.
I intentionally got the mac for school, I’m just looking for something to play in my free time.