Another couple of good books were written by Ziman, they are not rigorous, but when you sit down and actually read the text around his derivations you'll get a sense of what is actually going on in a solid.
Yu and Cardona hits semiconductors hard and is a great compliment to Ashcroft and Mermin who doesn't really touch them at all. Kittel has a decent mix, but is really the standard along with A&M.
Solid state is full of pick and shovel work, you have to deal with the dry intros out there, but after the fact you can do some really good work. Another good place to start is go back to the really old stuff, Slater or Seitz, they really knew how to write good books and you'll really get an appreciation for how far the subject has come.