One book that I've read recently that really stands out is Differential Geometry of Curves and Surfaces by Manfredo do Carmo. It's a bit outdated, and at times

One book that I've read recently that really stands out is Differential Geometry of Curves and Surfaces by Manfredo do Carmo. It's a bit outdated, and at times hard to read, but it has a lot gems that aren't well know (there is a bit at the beginning on estimating the length of a curve by counting the number of intersecting lines). I'd recommend it if you're looking for some math reading.