Some of these have been mentioned upthread; I'd class them all as being in the 'twitching autobiography' category; although they are very different in terms of literary style, I have to say all were enjoyable reads, I most recently devoured 'Birding on Borrowed Time':
Neil Hayward: Lost Among the Birds (US year list / mental health issues)
Adrian Riley: Arrivals and Rivals (British Isles year list / other lister issues)
Ruth Miller / Alan Davies: The Biggest Twitch (World year list / warning: contains mild sexual references)
Noah Stryker: Birding without Borders (World year list / great travel writing at cost of being selective about places / birds)
Phoebe Snetsinger: Birding on Borrowed Time (World life list / less novelistic although very candid, more catalogue of birds & places*)
I've not read 'The Big Twitch' yet, but a copy of Ken Kaufman's 'Kingbird Highway' just dropped through my door earlier today. I've only read the first page of the preface, but first impressions are head and shoulders above the rest in terms of the quality of prose - it is compared to Kerouac's 'On the Road' on the cover which is a very high bar to reach, but I can already see why the comparison is made.
To me Neil Hayward and Noah Stryker also pass literary muster, insofar as they are well written and entertaining beyond their birding subject matter - although I'm perhaps not the best person to judge this, as I'd just as happily read a series of species lists.
(* - maybe unfair, as she was killed while birding and the book was compiled from her manuscript, so she didn't have any chance to refine it)