After 35 years of riding motorcycles, I can tell you that if you stick with Metzler or Avon you cannot go wrong. I just tried a set of Michelins on my Sportster and was disappointed. Dunlop and Bridgestone are cheap crap. Metzler seems to be the tire of choice among Harley fans, while Avons are big with the metric crowd, however there is lots of cross-over in that mix.

Of all the bikes I've owned, the 1970 Triumph Bonneville shod with Avon tires was the best handling bike I've ever owned. I developed a deep appreciation for those tires on stiff suspension sport bikes ever since, and they will be going back on my Sportster as soon as the Michelins wear out.