when i was a newb, i was so scared of a flat tire (like most ppl in the commuting forum). i bought some specialized armadillo tires, and they worked!
as my tastes become more refined, i went to gatorskins, and then bontrager hard case. both are nice tires. the bontragers seem to last forever and ride nicer the longer you have them.
but then i started going on longer rides, and really wanted to enjoy the ride as much as possible. the panaracer pasela is fantastic. they are thin, light, and cheap. i haven't had a flat in about 1500 miles, but i think thats due to experience. the ride is soooo nice and a lot different from most of the tires out there.
now i put the tourguard models on my commuting bikes and the regular ones on my fun bikes. there are probably better tires out there, but not better tires under $20.