I run 26 x 2" Marathon Supreme tires on my 'commuterized' mountain bike and really love them. Pricey but the quality and lack of any flats in just abut 6000 miles of riding makes them worth while in my book. Still plenty of life left in them, so the cost per mile is pretty good. They replaced a set of standard Marathon tires, and the lighter weight of the Supreme model drastically improved the responsiveness of the bike.