if i may add my two cents
i was always getting flats in my neighborhood and i went to sheldon brown's bike store online to see what they sell.
i bought panaracer tourguide tires with kevlar lining. its true they are hard to put on the wheel but with the aid of carefully using tire irons and some patience they go on.
one time i felt a bump and i checked my rear tire and there was a thumb-tack size nail sticking out!!! the nail did not pucture my tire to my amazement.
to add-i keep my bike outdoors all year and the sidewalls get weathered so i have to replace the tires every spring. but i think they are worth the price.