VO full fenders. The plain aluminum kind, 45mm wide, for 700c tires. They say they are good up to 35mm tires--I'm running 35mm Nokian 106 studded tire and they *just* fit under the fenders on a 'cross bike.

Love the full-fender coverage, the VO fenders are even longer than standard. Not too much more than you'd spend on plastic fenders, but you have to drill your own mounting holes.