1) Watch "No Country for Old Men" (and optionally read it - it's a very faithful adaptation but you'll get additional character motivation/backstory from the book)

2) All the Pretty Horses - bildungsroman of two teenage boys chasing a way of life that no longer exists. One of his more accessible works, and the one that made him famous outside of literary circles.

3) Child of God - a light, quick read with a sympathetic portrait of a necrophiliac cannibal.

4) The Road - This will hit especially hard if you're a parent. A beautiful novel about not giving into despair no matter how dire the circumstances.

5) Suttree - in some ways the mirror of All the Pretty Horses - a young man leaves his way of life when it becomes clear that said way of life is vanishing. Based on McCarthy's real-life experiences growing up in Knoxville. Easily his funniest book. Probably the most compelling description of a specific milieu (1950s Knoxville underclass) I've ever read - simultaneously accessible - there are people who lived that life who are still alive - and yet impossibly remote.

6) Blood Meridian - Hard to describe. I wouldn't read Blood Meridian first because it's quite difficult, and because it has a way of making everything else (like...everything else, not just his other work) seem not as good.