It's worth noting that my wife is not your stereotypical gamer, and there's only a few video games she really enjoys playing as much as I do. :) The fact that she's hooked on this game lets you know it will appeal to a wide audience.
There's a few things the game could use some improvement on (such as the inventory screen not scaling well on split screen, or a little more variety in quotes/mobs/loot) but over all this is a great game. I would highly recommend this to anyone, especially since I see the GOTY edition, which includes all the expansions, tends to go on sale fairly often so you should be able to pick it up pretty cheap. Convince a friend to pick up the game with you and go have fun killing stuff. :D