Karen: Over on the Facebook Back Issue forum, there have been a lot of great covers posted, including a number of Sub-Mariner covers from the title's run in the 60s and early 70s. It was pointed out how frequently Namor appeared to be slugging it out with other super-heroes. This got me to thinking about how many covers feature hero vs. hero. There's something about two good guys slugging it out that is undeniably exciting, but when it's drawn in spectacular fashion by a great artist, it just elevates it to a whole different level. I'm posting some favorite hero vs. hero covers here for discussion, but you're free to bring up any others.
Doug: Karen offered me the opportunity to add to this one after she'd already started it. I chucked in the last three covers at the bottom -- I am loving all of them, however! Great topic, partner!
Doug: I'm adding this wonderful John Buscema Silver Age 2-parter, below: