I have a few.
David/Frank Hulk
David/McFarlane Hulk
David/Keown Hulk
Byrne/Byrne Alpha Flight
Willingham /Leeke Elementals
Stern/Byrne Captain America
Marston/Peter Wonder Woman
Wein/Perez Wonder Woman
Giffen/deMatteis/Maguire JLI
Michelinie/McFarlane Amazing Spider-Man
Michelinie/Larsen Amazing Spider-Man
Michelinie/Bagley Amazing Spider-Man
Broome/Kane Green Lantern
Broome/Infantino Flash
Johns/Kolins Flash
Fox/Infantino Adam Strange
Fox/Kubert Hawkman
Lee/Kirby Fantastic Four
If I could only pick one it would probably be the Lee/Kirby FF
