A close second would be my Schwalbe CX Compe cross tyres as again... have gotten amazing life out of these and used them in every season on every kind of surface and over nearly as many miles as the Hurricanes... have had no flats and they still look nearly new.

I also run Marathons and have also put some serious mileage on these but unlike the other Schwalbe tyres, have actually experienced flats with them. Thinking that the marathon tread has a tendency to pick up / catch debris and when the debris is a huge chunk of glass it can and has worked it's way into the tube enough to cause a slow leak.