The Marvel Masterworks series started and finishes with Amazing Spiderman. It is a very decent run of issues which mainly chronicles the Gang War saga. I did not care for the Annual with the "Iron Man from 2020" but I guess it had to fit in somewhere.
I also found the Introduction by Christopher Priest interesting in that his story regarding the evolution and forthcoming conclusion to the Hobgoblin identity is very different from what has been previously written over the years including interviews with all parties involved with the book at one stage or another. It is something the reader will never know for sure as it has been so many years now since these books were written.