i've used fortezzas, refuses, and armadillos. the armadillos are definitely the most durable and flat-resistant. the fortezzas are pretty in blue and worked just fine on my road bike, never did any skids though so i can't speak to their durability there. one finally gave out with a tear in the sidewall. the refuses are what i currently have. they've held up pretty well and i think what i like best about them is their ease in going on and off the rim... the armadillos can be a b*tch on the right rim, luckily once they are on, you rarely need to get them off.