Here's #12! Click here for the master list!
In many ways, #12 has become synonymous with the maxi-series, specifically the last issue of maxi-series.
Therefore, what better final issue of a maxi-series to use than the most famous maxi-series of them all, Watchmen?
The finale, as the book's original editor Len Wein noted at the time, was perhaps the least compelling part of the entire series, but it was still awesome - and certainly noteworthy!
Other notable finales of maxi-series include Camelot 3000 #12, Crisis on Infinite Earths #12, Secret Wars #12, Nextwave #12 (okay, it wasn't actually a maxi-series, but still, it WAS an awesome finale!), Punisher: Welcome Back Frank #12, Inhumans #12 (the Jenkins/Lee one) and some others.
Originally, I considered Marvel Super-Heroes #12, with the first Captain Marvel, but to be frank:
A. It's not that famous of an issue
B. He's not that famous of a superhero
That said, it's a great cover - it'd look good collected in a book!
Okay, some other notable #12s - Rapey McRaperson, Dr. Light, first showed up in Justice League of America #12. The Hulk met the Fantastic Four in FF #12. Spider-Man was unmasked in Amazing Spider-Man #12 (great issue, by the way). Son of Satan took over Marvel Spotlight with #12. And, as reader Purple Hayes notes, this WAS the number that Guardian died in Alpha Flight, which WAS a big deal, so certainly deserves a notation here. Juggernaut's first appearance in X-Men #12 was an early candidate, so it definitely deserves an honorable mention!
And...that's all I can think of, off-hand!
Tell me more!