My New Favorite Thing...

... is the Dover Chemistry/Physics series of books. They're fairly affordable paperback textbooks or reprints of classic manuscripts, so I don't feel bad about ordering them speculatively, or writing in them. I've purchased four so far on group theory/spectroscopy and mechanics, and they're all pretty fantastic. Plus, being paperbacks, I can carry them around in my purse, even though I don't have a particularly big bag. These texts typically have a pretty narrow focus, so while they may be less than perfect for undergraduates, they're exactly what I need.