Well, I finished Stranger in a Strange Land by Robert A Heinlein. "The most famous SF novel of all time" according to its cover.
I must say I didn't think much of it. Indeed, for about 50 pages, two-thirds of the way in, I thought it was the worst book I'd ever read.
It started OK - I thought maybe I'd been wrong to fear it - but then it was quite boring until the aforementioned 50 pages when it went massively downhill. It recovered a bit as I pushed through the last hundred pages over the weekend, but it's still not a book I particularly take anything from, or want to take anything from.
Like a lot of Heinlein, it is opinionated and self-satisfied, but unlike his shorter works, it lacks a decent story. The female "characters" are a joke, and the final sections seem to be an extended sexual fantasy of a kind that does nothing for me.
If anyone can begin to explain why this is so well-regarded, I'd like to hear it.
I should maybe say I read the original cut - the one that actually won the Hugo - and not the newer, longer edition, and on this evidence I can only be relieved.