There have been several characters to take up the mantle of Captain Marvel, but the Wasp is not only the most overlooked and forgotten candidate, but also the most suited to the role. The Captain Marvel name debuted initially with the character of Mar-Vell, the mantle's original bearer. He was then succeeded by Monica Rambeau, a fact often forgotten even by diehard Captain Marvel fans who may mistake a certain Air Force officer as the next in line after the original. Less notable (but nonetheless significant) names who'd take up the mantle afterward would be Genis-Vell, Phyla-Vell, Khn'nr, and Noh-Varr.
Eventually, the most famous and current version of Captain Marvel that is seen in the main continuity would arrive in the form of Carol Danvers. Arguably, the most underrated version of Captain Marvel doesn't even come from the current continuity, nor the main Marvel Universe. It's also a fellow Avenger who few would expect to ever pick up the mantle: Janet van Dyne, better known to readers as the Wasp.
The 2013 issue Age of Ultron #7 by Brian Michael Bendis, Brandon Peterson, and Carlos Pacheco showcases what the world would look like had Wolverine killed Hank Pym before he created Ultron. As a result, several noticeable changes are made to the world. One of the bigger changes is that Janet van Dyne is Captain Marvel. Her run doesn't last for long, though, as the former Wasp gets killed off in the very next issue. However, the fact that it happened to begin with speaks to just how underutilized and underrated the Wasp has been both from a fan perspective and even more so from a character perspective.
An Underrated Hero Finally Reaches Her Potential
The Wasp, despite being someone who has led the Avengers and has stopped major threats by herself in the past, is constantly left out of conversations that would place her among the greatest heroes Marvel has to offer. Then again, from a character perspective, that's almost apropos for a hero often stuck in her husband's shadow. The abuse that Janet has suffered at the hands of Hank Pym has been well documented by now, but one overlooked fact is how their co-dependent relationship has often forced Janet to be relegated to Hank's background.
She's overlooked because so much of her role in the Marvel Universe is unfortunately defined by her time with Hank rather than her solo adventures as the Wasp. In a world where Hank isn't alive, though, Janet is capable of reaching her full potential, which clearly is high enough to place her as a cosmic hero. It's a discovery that manages to be both validating and bittersweet for her character. The Wasp may be underrated in the main continuity, but without her husband, Janet is capable of being a prominent character that rivals the official Captain Marvel.