"After Virtue" - Alasdair MacIntyre.

This is a niche recommendation. Almost didn't mention it. The author died recently though, so it's important to the book nerds.

If your bag is Aristotelian virtue (and virtue based ethics) vs. emotivism (I favor the former), it's a good read.

Although extremely pessimistic.

(Lots of down time on the road, sorry/not sorry)