The Last Barbarians: The Discovery of the Source of the Mekong in Tibetby Michel Peissel was a pretty good read- certainly a lot better than the two reviews at Amazon give it credit for. Not just a travel book or a book about Tibet, this book covers a lot of things from the history and geography of Tibet to Peissel's rather boring and too-long musings on modern life. Those were easily skipped and I generally enjoyed the book. Peissel speaks Tibetan (a rarity in too many travel books) and doesn't complain much about the conditions (even when he had kidney stones, and you're allowed to complain about those). He does have some odd ideas, first complaining that modern life ruins our intelligence, but then pining for the days when Europeans travelled about Asia carried by coolies with tuberculosis. Those are the parts worth skipping- Peissel is better at Tibetan than concise writing.
All in all not really worth picking up, but if you're interested in Tibet, it's probably worth reading. Peissel also briefly writes about a later excursion to Tibet to study horses.