I had two punctured tires in three weeks right before I bought these. Since I switched to the Marathon Plus tires a few months ago, I haven’t had a single puncture. The Marathon tires come in two grades: normal and Plus, which is the more flat resistant of the two (Schwalbe also makes a model called the Supreme, which I haven’t tried). They are truly for everyday commuting, with tread and real heft. Most importantly, they have Schwalbe’s SmartGuard, a layer of “highly elastic, special india rubber” to help better protect your tubes from sharp objects.
The Marathon tires aren’t cheap — and it’s hard to tell whether it’s just been good luck or good engineering — but I feel confident it’s the latter. I ride a lot (28 km, two or three times a week, 10 months or so a year) and I used to get tons of flat tires, sometimes once a week. This month in particular is very bad for debris; it’s the thaw here in Toronto, so all sorts of junk gets left behind as the snow banks melt.
I’m sure part of why I was getting so many flats is due to the fact I usually ride an EZ-1 Recumbent. With a ‘bent, the front wheel is very lightly loaded and the back wheel is heavily loaded. I sit right on top of it (I’m 6’2″ and 240 lbs), so it probably carries 90% of my weight. I think this makes the tire more susceptible to punctures because I’m guaranteeing that anything sharp that doesn’t bend or move goes right in. I’ve ridden on a few other kinds of tires: Continental slicks (nice), cheapo knobbies (garbage), some satisfactory tires that came stock, and Primo Comets (dartboards).
I am riding under the same conditions, circumstances and in the same areas as when I used to get the flats, and haven’t had any trouble. Just last week I rode through quite a lot of glass with no problems.
[For a puncture-proof option you can opt for Stan's NoTubes System. However, they don't offer tires smaller than 26", so if you ride a 'bent with a 16" or 20" front wheel, you'll have to fashion one for yourself using Stan's conversion kit. The Marathon Plus is a simpler, less DIY option. -- SL]