Take Science Fiction with a grain of salt please. Most SF books sold are just fantasy and fiction and almost completely lacking in the science department.
Take Science with a grain of salt please. And make that a big grain. About a qubic kilometer will do.
Science in this list points to facts, knowledge and methods. So a theoretical treaty about black holes finds it's place here, just as well as a book about aerodynamics or marine ecology or a progamming manual. Yep, I lump all the dry stuff here.
Not many 'favourites' of course. I mean it's not the type of stuff one reads to be distracted. I read it once and try to remember it (the 'science' books) or I pick it up to look for something specific and drop it again (the 'manuals')
Only the later are used often and become actual favourites.