http://www.m-audio.com/products/en_us/XSessionPro.htmlThis controller is great, especially for the price - i got it for about £60.
4 sliders, crossfader, 12 knobs and 10 buttons.
Installation is piss and it's usb powered.
Very easy to configure for use in Traktor and AL via midi learn.
It's bigger than I expected, about the size of a small "real" mixer which is good because everything isn't too cluttered.
Of course there are better controllers, but for the price this is excellent.