I use my mountain bike for about 50% off road use and 50% commuting. About every few weeks glass seems to work its way through a hole in my tire caused by a nail and punctures the tube. Each time I take it to the bike shop I get them to replace the tube and patch the hole. I have had to do this about 4 times now in the past 2 months. I am finally fed up and am ready to get a new tire. Does anyone have any recommendations for me on what tires would provide the best puncture resistance? I would appreciate if ya'll could give me specific tires to look at. Also, do I want a tire that has a high tpi or a low tpi and does the weight matter as far as how strong the tire is or does that just matter for how fast or slow you want to go?