The 1979 book The Art of John Byrne featured a couple of nifty illustrations for that era of the Marvel Universe...
This one in particular is a joy, capturing my favorite X-Men and Avengers teams, with the Fantastic Four thrown in for good measure. Byrne wouldn't take over the FF until two years later in 1981--this was a harbinger of things to come!
The cover to this book featured Byrne's own creation, Rog-2000, driving terror into the hearts of Spider-Man, Wolverine, Scarlet Witch, and the Vision.
If you ever find this book at a con, it's very much worth having! Nuff Said.