Look up the word 'ignored' in the dictionary, and you'll find Question's face (or...the opposite of that?). This detective/conspiracy buff is determined to discover 'The Truth' at all costs, risking his life all the time in his fight against The Man. Besides being one of the smartest characters in the DC universe and a frequent intellectual rival of The Riddler, Q is also among the top martial artists, learning his techniques from Richard Dragon. The original Question has since been replaced by former Gotham City police officer Renee Montoya (Madre de Dios!) in the comics after Vic died of lung cancer. And the poor man's legacy is that still to this day that he's just a cheap ripoff of Rorschach (despite that being the other way around).
The only piece of media that gave him the relevance he deserves was the animated show Justice League Unlimited, in which he was voiced by Jeffrey 'The Re-Animator' Combs. Originally just a creepy but hilarious character grumbling about conspiracy all day, he eventually ended up as one of the most important characters when Batman hand-picked him as the only member of the JL who can discover the connection between Lex Luthor and Project Cadmus. Apparently, The World's Greatest Detective has more faith in Question's detective skills then in his very own. That has to count for something, right?
Aquaman is the quintessential cool-to-hate superhero, and all we have to blame is the 70s animated show Super Friends, in which he was portrayed as weak, useless, and WAYYY too into fish. Many of the A-haters weren't even alive back then, but somehow the reputation stuck (South Park, Robot Chicken, and Family Guy haven't helped much). Aquaman is a wuss in the eyes of most people, and there's nothing DC can do to make it change (but not for lack of trying).
In reality, the character today is pretty hardcore. One of the greatest fighters (on roughly the same level as Wonder Woman) and a brilliant strategist, Aquaman is not someone you want to be on the bad side of. He is already bad enough when one has to engage him one-on-one, but that is rarely the case. After all, with a city full of badasses just like him, and all the billions of terrifying creatures of the deep waters following his orders to the letter, he has the mightiest army on Earth. He can look someone like Lex Luthor dead in the eye and give a warning about staying away from his waters, knowing no one is stupid enough to call his hand (or, for a while, hook). He's like an underwater Conan The Barbarian, sitting on his mighty throne, just daring the land-dwellers to mess with him. The old saying from Alfred T. Mahan goes like: "Whoever rules the waves rules the world." To which Aquaman would probably say: "King of the seas, remember?"
Krillin is, possibly, the most underrated fictional hero of all time, and definitely the most underrated fictional human being. Known to people who don't watch Dragon Ball Z as a helpless bald midget who dies all time, Krillin is analogous to worthless cannon fodder on the internet. And while it is true that he is short and, for most of the series, has no hair, the rest is not exactly accurate. Krillin first shows up on Episode 14 of Dragon Ball (Goku's Rival), meaning that he is established as series canon for 495 episodes across DB, DBZ and DBGT. During the entire series, he dies at the grand total of 4 times. While that makes him the record holder of the series, it isn't exactly what anyone would call 'all the time'. By comparison, Goku and Vegeta both die twice, and Piccolo dies 3 times, meaning Krillin isn't that muchmore prone to dying than the more powerful characters.
Quick sidenote for those not familiar with Dragon Ball Z: death doesn't have a whole lotta weight on this show.
Also, Krillin actually survives a lot of seemingly fatal situations. Not counting Yajirobe (who barely participates), Krillin is the only human survivor of the Saiyan Invasion, and in the Namek Saga he outlives Vegeta by 9 episodes. He is also the only character to play a role in all 3 fights against Legendary Super Saiyan Broly, surviving all 3 encounters. As for usefulness, he is the proud inventor of the Kienzan (Destructo Disk), a move so awesome that pretty much every character ripped it off right away (Master Roshi had similar experiences with the Kamehameha, proving that humans come up with the best attacks ever).
And, finally, some food for thought: the power difference between Goku and Krillin is not nearly as huge as the one between Superman and Batman, and The Bat never had to deal with people calling him weak and useless. He is useful in different ways, and we accepted that. Bruce invented gadgets and provides funding for the League to remain useful (also being the most cunning, intelligent, brutal detective helped some). Krillin transcended the limitations of the human body to walk in Goku's footsteps. He remained relevant long after any human has any business being relevant in the series. By the end, he is the strongest human who ever lived (Uub kinda don't count, being the reincarnation of Buu and all) and could beat planet-wiping dudes like the Ginyu Force with both hands tied behind his back. Krillin is a character who deserves awe and respect.
Although, to be fair, he DID marry a robot and somehow had a kid with her. C'mon, Krillin.