Paul, we could pull Webb into the 25-year window with The
Emperor's General, certainly his most philosophical exercise.
Of course, the whole idea of a "best" in novels is ridiculous.
So many fabulous novels have simply disappeared: The
aforementioned Edwin Mullhouse, Paul Rogers' A Child
of the Century, Frederick Boechner's four novels about Leo
Bebb, Real Money by Louis P. Jones, The Dolly,
DollySpy by Adam Diment, any of which I'd gladly
read again, right now.
If you ever want a depressing experience, look over the
publisher's lists for the upcoming year. Book publishing has
always been PC, but it's now totally rotten.