* Defining "appearance": Does it count cameos, flashbacks, or just full-fledged roles?
* Counting issues: Some characters have appeared in thousands of issues across multiple series, making it hard to track accurately.
* Varying sources: Different sources may list different numbers, and some information is outdated.
However, some contenders for the title of "most appearances" include:
* Superman: He's been around for decades, appearing in countless issues of his own titles and guest-starring in many others.
* Batman: Similarly, Batman has a long and extensive history, appearing in numerous issues and even surpassing Superman in appearances in some recent years.
* Spider-Man: He's another long-running character with a vast amount of appearances, both in solo and team-up titles.
It's likely that Superman, Batman, and Spider-Man are vying for the top spot, but the exact answer is difficult to determine with certainty.