In Trouble Again: A Journey Between the Orinoco and the Amazon by Redmond O'Hanlon. "O'Hanlon's approach to travel borders on the lunatic" Publisher's Weekly.

O'Hanlon has a couple of other similar books -- one for Borneo and one for the Congo, both of which are also good. All are quite humorous. A more recent book of his (Trawler: A Journey Through the North Atlantic about life on a fishing boat) I never finished.

A very interesting one, similar to the "Congo" book above was published in 1799 (!): Travels in the Interior Districts of Africa by Mungo Park. Written in a more serious nature that O'Hanlon's books but still involving series of misadventures similar to O'Hanlon's with the exception that they were actually much more dangerous. I believe the author made a second trip but never made it back to write a second book.

There are a number of World War II true-life spy stories. One good example is The Double-Cross System: The Incredible True Story of How Nazi Spies Were Turned into Double Agents by J.C. Masterman who was directly involved. It was first published contemporaneously (1945) as a confidential report for the British Intelligence higher-ups and has been publicly available for some time. There are other first-hand books about the various intelligence activities of WWII. This is a good one to start with.