Slim in pages but expansive in scope, Philip Roth's Everyman is a meditation on life viewed from it's endpoint. You can still see glimpses of the younger, vintage Roth (it wouldn't be a Roth novel with at least one sexual escapade intimately detailed), but the main thrust of the novel is one of sadness and contemplation, as the nameless protagonist review the life he led as his few remaining friends and relatives preside over his burial.
If it sounds rather depressing that's because it is, but Roth is brilliant enough of a writer to tell the story in such a way that you're compelled to keep reading straight through. I started this last night with a cup of coffee and finished it this morning reading to my son while he ate some cheerios and I had another cup. There's no real plot to speak of: just a series of reminisces about past glories and failures, and regret at the things we've done and haven't done.
Everyman is one of Roth's more accessible books, although I don't think it's so representative of his work that I would use it as a starting place.