The 2.35 Nevegal front that chelboed mentioned is WAAAYYY better than the WTB Veloci front. I've got both and ditched the WTB after about three rides. The Nevegal has similar rolling resistance but tons more grip and a nice smooth feel.

As for the rear, that Velociraptor has a great tread design for loose soil and some good on center grip. The Nevegal doesn't have quite as big a paddle but has great off center grip which not only helps on corners, it comes in to play on rocks and roots as well.

I'm going to mirror chelboed's recommendation here. I'd add Kenda's DTC variants of the Nevegal to the list, since they should wear longer on center.