Thompson's 1971 gonzo masterpiece remains the Las Vegas book — a drug-fuelled tear through the early-1970s Strip dressed up as the coverage of a motorcycle race and a narcotics conference. The plot is incidental; the book is really about the death of the 1960s and the moment American optimism flipped over into a more cynical national mood. The Strip becomes the backdrop for Thompson's diagnosis of that turn.
Many of the casinos he describes are gone, demolished, or rebuilt unrecognisably, but the sense of vertigo is intact. The 1998 Terry Gilliam film with Johnny Depp is faithful, weird, and worth pairing with the book. Read it before or after a Vegas trip; reading it during is probably a bad idea.