Batman and Superman are currently locked in a heated popularity contest, driven by the much-anticipated movie "Batman v. Superman: Dawn of Justice."
But while fans debate the merits of each superhero, comic collectors are asking: who's the shrewder investment?
After all, both wildly popular characters got their start in comic books. Superman burst on the scene in 1938 in Action Comics #1.
Batman debuted in 1939 in Detective Comics #27.
That timing is key, says Vincent Zurzolo, co-owner of Metropolis Collectibles, metropoliscomics.com, the world's largest vintage comic book dealership, and comicconnect.com, its online auction site.
"Superman is the world's first comic book superhero," Zurzolo said. "He influenced all who followed, including Batman."
"Comics featuring a character's first appearance are typically the most valuable. For these reasons, I believe that Action Comics #1 will always be the gold standard, " Zurzolo said.
In the last decade, four high-grade copies of Action Comics #1 have sold for over $1 million—all through Zurzolo's company, which has the Guinness World Records to prove it.
The highest book sold for an unprecedented $3.2 million (which Zurzolo purchased).
In contrast, only one Detective Comics #27 has broken the seven figure threshold, and just barely.
So is Batman a weak comic book investment? By no means, Zurzolo said, "If a high-grade copy of Detective Comics #27 came on the market today, it would perform very well."
In fact, when it comes to compelling supervillains, Batman overpowers Superman, and that also impacts comic book values.
"The Joker, Riddler, Penguin, Catwoman, Two Face…Batman has a deep bench of great villains," Stephen Fishler, CEO of Metropolis ComicConnect and Zurzolo's business partner, said.
"But name one well-known Superman villain besides Lex Luthor," Fishler, who created the 10-point grading scale that is now the gold standard, said. "Most people can't."
So, at the end of the day, which character should aspiring comic book collectors choose?
"My rule of thumb is to collect what you love, so pick the character that appeals to you," Zurzolo said. "Or collect both. Just do your homework. Make sure you're buying from a reputable seller, paying fair prices, and most of all, having fun."