I've had 26x1.75" Marathon Plus tires on my Novara Safari fat-tired touring bike for a year and am completely satisfied with them. I've put about 2,500 miles on them, including a 1,200-mile tour on pavement, railtrails and canal trails. I've had only one puncture, a miracle in everything-has-thorns Arizona. The tires have a built-in puncture-resistant belt, so are heavy, but so what? The 1.75" width is fine for pavement, while allowing for unplanned off-pavement riding. The tires show virtually no sign of wear. I ordered the tires from www.biketiresdirect.com
, which seems to carry about every kind of tires. The cost was about $34/tire -- pricy, but worth it for the reliability and long wear.