Two Worlds 2 hands down. You have almost complete control over what type of spells you create, and the fact that a lot of them are affected by the physics engine is awesome. Nothing beats summoning a storm of 2 dozen anvils right above your enemies head.
I also like the magic combat in Demon's and Dark Souls. It's really fun online when you can creep up on opponents disguised as a Christmas tree.
Meet the new love of my life-- http://itotd.com/view/80/