Warning: This contain spoilers.

Great movie.
Josh Brolin's character sure was dumb but I have to give him credit for lasting as long as he did and also for even wounding the psychopath played brilliantly by Javier Bardem (he had me scared almost 100% of the time when he was on screen - that part in the gas station was the scariest). I loved the wife at the end refusing to call like he asked to. And that crash made me jump, I really was not expecting that.
The special effects and makeup are average. The cinematography, editing, sets, story and music are good. The acting, directing, costumes and script are great.