I am a medical student in Italy. As far as I know, almost everyone in my University use Lehninger Principles of Biochemistry, as it said to be the most comprehensive.
I find it just too stuffed with "words", a feature which puts off students who really want to learn this fantastic subject.
On the contrary, Stryer's Biochemistry is systematic and very well structured. The explanations are clear and concise.
As to Devlin's biochemistry, it must be said that it offers many more medical insights than the others, but it seems to me to lack clear and easy-to-study explanations upon more "traditional" concepts: glycolysis, oxidative phosphorylation and so on.