Mr. Tuffy's all the way. I started riding with Mr. Tuffy's with cheapo tires six months ago. I haven't had a flat the whole time. Well worth the small weight gain. I don't even bother with puncture resistant tires, because the Mr. Tuffy's work fine on their own. I've even pulled out a couple good sized chunks of glass and rock from my tire, which normally would've resulted in an instant flat.