My favorite part of my book collection; my William Gibson first editions. The copy of Neuromancer is the UK first edition; still need to get my hands on the American edition. At the top of the pile is the first edition paperback of Neuromancer which was released in America in ‘84, two years before the hardcover first edition.
The second copy of Mona Lisa Overdrive is the unedited proof copy; which is something usually put together for editors and for the purpose of advertising/trying to create buzz for the books release.
The copy of Idoru with the black spine is the UK first edition. My copy of The Difference Engine is from the UK as well. I just really like the UK editions; I often prefer their cover art.