I did not enjoy Mary roach.
It was a while ago. I attempted to read "Stiff." I didn't finish I'm pretty sure. I think my opinion of Roach suffered as I had recently read both Complications and possibly also Better by Atul Gawande and I found I enjoyed his writing style much more, while bth authors were discussing similar subject matter (bodies, medicine). The book seemed "pop"-py to me. It was not as bad as Gladwell (I read "Blink" and hated it) but I remember feeling as if the subject could have been covered better by others.
See, and I haven't read Stiff and don't want to. Packing for Mars is all I got - and it's very poppy. But it's an "everything you wanted to know about space travel but were afraid to ask" manual that spends a chapter and a half on the toilet on the space station and "poppy" is the way to go.
Complications is (somewhat sadly) definitely better than Better. There was supposed to be a third but it looks like that never came out. The Checklist Manifesto I found valuable, but it expands beyond the realm of medicine - so in that way very different from better. I would pick either Checklist or Complications, I am wondering if you would prefer Checklist because it's broader - but Complications is very good.