I have read a large number of autobiographies - but have not re-read many, because most are not much good. As a genre, autobiography is of generally low quality.
Which ones were good?
John Cowper Powys, for one. I have heard this described as the best autobiography ever written. Certainly it must be one of the most eccentric. Powys was a one-off: a ?great novelist and a very strange man indeed. Like all good autobiogs, it is highly selective - Powys does not mention any women!
C.S Lewis's Surprised by Joy is another that I have re-read several times: it is probably the most famous spiritual account of the twentieth century - very frequently quoted in Christian circles. Like Powys, he leaves out almost everything about women - except his mother. Maybe this is significant?...
There are semi-autobiographical accounts of a person's life in a particular place - but short on personal details; such as Thoreau's Walden, or the more recent Ceremonial Time by John Hanson Mitchell - both of which I love. But these hardly count as formal autobiographies.
I was deeply impressed by Beyond a Boundary by C.L.R James - an intoxicating account of his life, cricket - mostly, politics and social analysis by the Anglicized Black Trinidadian Communist.
One autobiography which made a big impact on my work was What mad pursuit, by Francis Crick. From this I learned certain things about how to do theoretical biology which helped make me the scientist I am today (ahem).
A scientific autobiography of clear genius, but which I only read a couple of years ago and haven't yet gone back to, was Erwin Chargaff's Heraclitean Fire: simply as a writer he stands among the best of his era. The book also impressed by its burning, passionate honesty and indignation at what was happening to science.