I have been 90% bike commuter since I left for law school in August of 2006. Before that I was sporadic, but in the 90s, all I had was a 1990 Nishiki Olympic 12 speed and a Diamond Back Ascent mtb. The mtb is gone (my brother took it with him to college one year and at one point sold it for food). My bike is similar to the one depicted here. I did not have the secondary brake levers or the rack.
I got rid of the gearing and went to a single speed coaster to minimize my upkeep. In spring of 2007, the tire Drew gave me was so thin, it picked up a piece of glass and kept it hidden from me while I changed the tube three times, wondering what kept popping my tube.
Once I brained up and found the hunk of glass, I realized I would have to buy a new tire. So, I researched the superest dopest most awesomest tire that a commuter could want. I wanted a tire that could take bullets to keep me from flatting on the way to class. My research turned up the Specialized Armadillo All-Condition tire.
I paid top dollar for the 700X23c tire that went on my Nishiki. Since then, I have not flatted, pinched, or punctured at all. I weigh roughly 200 pounds, and most of that is in my bum. So, the rear tire has to stand up to quite a bit. I have lost 2 tubes since installation, but in both instances, the cause was the valve breaking. That tells me the tube valve will fail before the tire allows the tube to puncture.
I also determined at one point that the tires on my 20 year old Cannondale touring bike needed replacing.
Same thought process here, but the research was already done. FYI, I have this bike setup to haul a Bob trailer. So in spring of 2008, back I went to the bike shop that liked to give discounts to members of Willamette's racing team. I needed the 10% off, because the tires were each $50. I bought this bike from a friend for $50. Since then, same result. No pinch flats or punctures. In fact, since I went to these tires, I have never flatted on either bike. Typically the valve stems fail in the garage as I am pumping up before I ride.
I consider the extra dollars spent on these tires to be worth the money saved in tubes, time, frustration, and confidence.