Holy Rollers are some of the thinnest, least protected tires around. Between the knobs, there's just about nothing to stand in the way of a puncture.
Schwalbe Marathon Plus are the ones to buy!
Schwalbe Magic Mary BikePark are good too, but no nobs.
There is one or two more Schwalbe's with great protection, but I cant find my list.
Schwalbe Hurricane is one step above average.
Why all Schwalbe? Because they list a Protection and Durability rating on their tires on their website.
Couldn't agree more about the Schwalbes. I use 26"x2" Marathon Plus tires on my commuter and they are the best street tires I've ever used. NO flats and low rolling resistance combined with great traction. I've used the Holy Rollers before, and had good luck with them.