Have to go with the classic DETECTIVE COMICS #27.(Of the popular covers given.)
I feel there are a few that have been slighted.
One of my first BATMAN comics I bought as a child: BATMAN #453 .Mike Mignola, y'all. This is what I imagine one of Bats' metal album cover would look like, had Bruce decided Batman was to be a heavy metal frontman.
One of the more recent covers that I found to be stunning was Greg Capullo's variant cover for DETECTIVE COMICS Vol. 2 #27. Very 1989.
But what about BATMAN #423? Back when I was in the 4th grade in 1990, this was one of the most sought after books for any 10-year old comic book reader. This cover set a new artistic trend for Batman.