I've used the Oxygen before, and it was pretty neat.
http://www.m-audio.com/products/en_us/Oxygen8-main.html
Retails at 180 bucks, but you can find it cheaper very easily. The one I got to jam on was purchased for a hundred flat, I know. What I like about it is the simplicity and yet the surprising versatility, for the most part. It's something I'd definitely recommend to anyone starting out and feels that they're actually ready to use some decent hardware. I'm not a fan of too many bells and whistles on the controller itself. I think it's kind of wasteful when you can get software to manage all of that just fine.