Or whatever you'd call them. I love reading them. Into Thin Air is the quintessential mainstream example, but I've read a bunch, and would love to read more. In addition to Krakauer's, I've read:
* The Climb (Anatoli Boukreev), his account of the 96 Everest disaster, since he felt slighted by Krakauer's account of him.
* Forever on the Mountain, on a 1967 I think group many of whom died on Denali
* Eiger: Wall of Death, an outstanding account of the first handful of people to try, fail and succeed in climbing the north face of the Eiger
* K2: Life and Death on the World's Most Dangerous Mountain, Viesturs' account of a big disaster there
and probably a few others, currently reading Where You'll Find Me, on the climber who died doing a northern presidential traverse in NH's Whites not too many years ago.
What else is a must-read in this genre?