The Punisher by John Romita

1983 - Hobgoblin Model Sheet by John Romita Jr.

Black Knight by Paul Smith

Managed to snag this Black Knight sketch from Paul Smith!

Huzzah!

Late 1980s - Hulk by Dale Keown

1992 - Daredevil by John Romita Jr

Captain America by Mike Zeck

1986 - Daredevil Love And War Graphic Novel sketches

By Bill Sienkiewicz (as if I had to tell you that!)

Doctor Strange Head Sketches by Kevin Nowlan

Spider-Man by Bob Layton

Punisher Head Sketches by Mike Zeck

Aurora by John Byrne

1985 - Daredevil fan sketch by David Mazzucchelli

The Mighty Thor by Ron Frenz

Hercules vs. Iron Man by Bob Layton

Vision and the Scarlet Witch by Chris Samnee

Nightcrawler by J.H. Williams

http://www.comicartfans.com/GalleryPiece.asp?Piece=1126546&GSub=33855

Wolverine sketch by John Bolton

1985 - Doctor Strange by Rick Leonardi and Al Williamson

Inked by Al Williamson in 1989.

http://www.comicartfans.com/GalleryPiece.asp?Piece=247066&GSub=17716

1978 - Cyclops and Phoenix by John Byrne

1981 - Captain Mar-vell by Pat Broderick