Ok, how about this for an idea. We take it in turns to post a favourite (British spelling) comic cover every day. This went really well on the comic fan website that I used to frequent. What we tried to do was find a theme or subject and follow that, until we all got bored with that theme. I'd like to propose a theme of letters of the alphabet. So, for the remainder of October (only 5 days) and all of November, we post comic cover pictures associated with the letter "A". Then in December, we post covers pertaining to the letter "B". The association to the letter can be as tenuous as you want it to be. For example I could post a cover from "Adventure Comics" or "Amazing Spider Man". However Spider Man covers can also be posted when we're on the letter "S". Adventure Comic covers could also be posted when we're on the letter "L" if they depict the Legion of Super Heroes. So, no real hard, fast rules - in fact the cleverer the interpretation of the letter, the better, as far as I'm concerned.
And it's not written in stone that we have to post a cover every day. There may be some days when no cover gets posted. There's nothing wrong with this, it just demonstrates that we all have lives to lead.
If everyone's in agreement I'd like to kick this off with one of my favourite Action Comic covers, from January 1967. Curt Swan really excelled himself here.
Discussion and voting on future monthly themes takes place on the "A Cover A Day: Nominations, Themes and Statistics" thread. Click here to view the thread, or here to go to its last reply.
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This is the cover that made me think of this topic in the first place.

An unexpected villain for a solo cover
Merlyn the archer takes over a Green Arrow/Black Canary cover. I never heard of him until he showed up on the Arrow TV show.
Baron Weirwulf is introduced with this fine cover by Don Newton.
It's a three bagger with the Superman of 2965 - KIar Ken T5477 (There must have been a LOT of Klar Kens before him!) starring Superman VII.
Another lady who isn't the title character, courtesy of the Grand Comics Database.

Tailgunner Jo was a very interesting six-issue limited series from 1988/1989, which I greatly enjoyed. Jo is a young girl whose consciousness has been implanted in her cyborged father's brain, after she was born with catastrophic damage from pre-natal exposure to teratogens. She lives in an fantasy kingdom reminiscent of Alice in Wonderland, and also acts as a "tailgunner" for her father's cyborg weaponry, as he seeks to take down the corporation responsible for his daughter's condition. The cover on the left shows Jo's father, and is the only one of the six that doesn't feature the title character. The one on the right does show Jo, here seen on a quest with friends and companions in her fantasy realm:
This name was likely inspired by the infamous Senator Joe McCarthy, whose nickname was "Tailgunner Joe."
This cover features Mumen Rider. Although he is physically weak, he is the most truly "heroic" of all the heroes that Saitama encounters in the series. The name "Mumen Rider" is a parody of "Kamen Rider".