Including JMT record-holder Brett Maune.
Twice.
Including "Flyin Brian" Robinson, first person to hike the PCT, CDT, and AT in one season.
http://en.wikipedia.org/wiki/Brian_Robinson_(hiker)
and one of the nicest guys you'll ever meet.
Great Washinton Post article on one of Brian's failure races.
Does it help that the race organizer is a sadist?
(no first aid, placing mandatory check-in at a rattlesnake den, requiring contestants to pay in full for any SAR)
http://blog.washingtonpost.com/why-we-compete/2007/04/curiosity_1.html?hpid=topnews/