As single play: Legends of Dawn
As single play: Legends of Dawn
Divinity 2 was a fun one as well. It had a very old school feel to it which I enjoyed. But it didn't feel like a single player WoW like the OP was suggesting. Still though, I really liked and was surprised with how much fun I had with it.
As for Amalur, I played it on XBox and paid like $2 for it brand new. Looks like Amazon has a boxed copy of the PC version for $15 if you're interested there.
http://www.amazon.com/Kingdoms-Amalu...gdom+of+amalur
A physical PC copy was for sale on Amazon for around $15 today, only a few copies left. I am pretty sure my wife is buying Kingdoms of Amalur for my birthday, so I will have to hold out. I have read nothing but good things about the game, especially about the combat system.
Shroud of the Avatar. It's a MMO which can be played solo, even offline.
edit: ooops, necro, sorry, found this via google looking for something.