If I may, I'll go ahead and put in a good word for a few others:

Marvel Premiere 55: A Simon Williams Wonder Man solo story. That alone makes it unusual, but it's effective as well. In this, he goes to investigate what became of components of his former business operation and finds they've fallen under criminal ownership.

Sub-Mariner 57: Beautifully illustrated story by Bill Everett bringing his 40's and 50's-era character Venus into modern times. They say they don't make them like they used to, but if they'd just stand aside and allow craftsmen from those bygone eras to do just that, the results might just blow us all away...

Years before we were all plugged into the Matrix, billionaire Simon Boar was kidnapping innocents and hooking them up to his people-draining machines, and enforcing his will with a shadowy figure dressed all in black...

The Destructor was Atlas' Spider-Man created by Archie Goodwin, Steve Ditko and Wally Wood, lasted 4 issues.

The Grim Ghost created by Michael Fleisher and Ernie Colon. I think Todd McFarlane may have read this book in his younger days. Lasted 3 issues.

Wulf the Barbarian, the first 2 issues were written and drawn by Larry Hama and inked by Klaus Janson.

Only 1 issue for Demon Hunter by Rich Buckler, Buckler brought back the character as Devil Slayer at Marvel.

This was my first exposure to Conan the Barbarian and it was courtesy of the powerhouse team of Roy Thomas, John Buscema, and Ernie Chan. At the time I had only dipped my toe into Marvel Comics waters via reading a few issues of the Fantastic Four. But when I opened this issue and saw that The Watcher was narrating the story, it pulled me in immediately.

Suffice it to say, there were a lot more Conan comics in my future after savoring this one. A hidden gem indeed :-)