CORRECTION:

The Conti tire I have is a Conti CityRIDE 700 X 32C. I have had zero flats with it since I installed it.

I have had very good luck with all the Conti tires i have had, but as I said before, I don't get a lot of flats in general.

Poor Cyccocommute and his experiences mentioned earlier are not the norm... Continental does not have a 100% defect rate among the general population. I recall years ago that Contineental TownandCountry tires were super difficult to get properly mounted much more often than you would expect, but otherwise I cannot recall any repeated problems with them.

However, Schwalbe, Panaracer, Vittoria, and Kenda all make good tires. I have heard a lot of people talking about their bad experiences with Kenda, and they certainly don't have the tight quality control of the more expensive tires, but the front tire on my bike right now is a Kenda Kwick Bitumen 700 X 38C and it has been awesome. But it is not the $9 version. I suspect they have different levels of QC for different tires.

I worked for a bike company that specced Kenda tires almost exclusively, and cannot recall any problems (except for road tires with different colours in the tread not lining up quite right - the tires were still nice and round - but if you stared at them while you rode you would get seasick). They certainly had a lower defect rate than Specialized tires - so many treads peeling off and beads ripping out of sidewalls that I couldn't count them all... although the tires that were not defective were very good.