I'd like to nominate
Three Men in a Boat (1989) by Jerome K. Jerome.
According to
wikipedia,
"...since its publication, Three Men in a Boat has never been out of print. It continues to be popular to the current day, with The Guardian ranking it #33 on The 100 Greatest Novels of All Time in 2003, and Esquire ranking it #2 in the 50 Funniest Books Ever in 2009".
Available in MR