Graduate Texts in Mathematics 
Graduate Texts in Mathematics, Undergraduate Texts in Mathematic [2.18 GiB]
An almost complete collection of the Springer "Graduate Texts in Mathematics" and "Undergraduate Texts in Mathematics" series. I also included what I could find from their "Texts in Applied Mathematics" series, but they're sparse.
UTM doesn't have official volumes, so I made my own, somewhat arbitrary, numbering system for it. Their organized sort of by topic.
Links:
