In no particular order...

In regards to non-fiction, you basically haven't lived if you've never read The Book of General Ignorance. Look it up.

As for classic works, Shakespeare's Merchant of Venice is an undersung masterpiece. The subplots and controversy it brings to the table is not only way ahead of its time but downright brilliant. (Reminds me of how scholars argue over good ol' Austen's P+P being satire or naaah.) Shakespeare, beyond all the sex jokes, never quite lets you know HIS opinion; only those of the characters he creates.

If you like history and also brilliant writing, check out Sarah's Key by Tatiana de Rosnay.

It's originally in French (can't recall the the translation I read) but it was glorious from beginning to end. A really captivating book.

I'm also a fan of legal thrillers. I read John Grisham's The Appeal on the beach in San Diego in two afternoons. Couldn't put it down, and also conveniently "forgot" to put it back on the shelf in the vacation rental...ended up taking it home with me. Oops.