Not many publishers turn out good technical books in physics, astrophysics, and mathematics. Until recently, I would have said Cambridge University Press, Princeton U P, and Springer. This was before Springer decided to embrace sucketude and start putting their books in cheap, crappy bindings.
I have quite a few Springer books, and the older ones are well bound and open flat. The newest ones have stiff, cheap, crappy glued bindings, and won't open flat and stay open. I hate that.
Cambridge U P is the gold standard. Lots of good books, mostly affordable prices, and nice bindings that open flat. Princeton is also very good.
Authors would do us a favor by avoiding Springer - at least until they recover their senses.
Based on what I've read elsewhere, Springer seems to be committed to crap all the way. Unfortunately they still publish some important stuff.