I'm constantly on a quest for a sturdy rear wheel.
I'm a big boy - 6'3" and 240lbs or thereabouts - and the Achilles' heel seems to be the back wheel.
I'm currently riding a Cannondale T2000 "touring" bike - switched from a real road bike - because there's more room for fatter tires, which I figure will give better shock-absorption properties. (During the winter, I ride with 35-38 width "touring" tires; when the weather is nice, I pare down to a 28-32. My old Cannondale road bike would max out at 25, due to the tight geometry. I HAVE been getting more miles since I switched to the slightly-fatter tires, but would love to get more.)
I've always used standard laced-up 36-spoke wheels. Currently I'm trying an MA3 rim, after somebody suggested the hard-anodized rims may actually be more brittle. I've used MA40s, T520s, Open Pro, various Sun, Campagnolo, etc. Seems like after a year, or less (I average 4800-5500 miles/year), I've got an eyelet or two pulling out of the rim. Or spokes breaking at the right-angle hub end. (Which I generally attribute to a poorly-tensioned wheel.)
I try to exercise all possible caution - I avoid road hazards wherever possible, etc. I think I'm just outside the design-specs. (Road bike stuff seems designed for guys who are 6 inches shorter and 80 pounds lighter.)
I'd be willing to pay a premium price for a long-lasting rim. I was looking at the Spinergy, etc., etc., but non-spoke designs seem to come and go.
Any excellent advice from y'all would be appreciated. (Worst case scenario - I go on like I am, replacing the back rim once or twice a year. Sure beats the alternative - driving somewhere in a car! GAG!!!)