Conti Grand Prix 4 Seasons.
I get about 2000 or so miles on a set and even when the side walls look ragged I get no flats. I haven't had a flat in 2 seasons (4000 miles so far), so they seem durable
Trouble is I got a couple of pairs a few years ago from Bikes Tires Direct at about $35 ea. and they are now $60 ea.. Ouch !.
Steve B.