I have to agree that as far as flat resistance goes, Armadillos are beyond reproach. I have yet to get a flat with one with thousands of miles on various sizes of tires on my fleet of bikes. If you depend on your bike to get you somewhere on time ( such as your job ) you won't go wrong with Armadillos. The Specialized Flak Jackets are another matter - they seem slightly worse than average.
Also, I have had very good luck with Continental Gator Skin Ultras, as good as the Armadillos. And Vittoria Randonneurs have been good to me - these were on a Novara Big Buzz commuter I bought in February, and just went past 1000 miles without a flat. In fact, I have done a little over 5,500 miles in 2004 without a single flat for the year so far.