I definitely agree about Colossus. He joined the X-Men in GIANT SIZE X-MEN #1, circa 1975 same as Nightcrawler and Storm did, but from how he's often treated by some writers and alternate media, you'd have assumed he was a member of Generation X or something. If you want his best moments, it usually is best to stop reading after the start of the 90's. Hell, I wouldn't be surprised if the average fan was unaware that Colossus was with the X-Men for about five years before Shadowcat came along. Part of the problem is that after the 90's started, he starting doing more oddball stuff. His "is she or is she not a demon or evil" sister died, and he moped, joined the Acolytes, moped some more, got insanely jealous of Pete Wisdom when he was dating Kitty, moped some more, faded into the background for several years, was able to touch/kiss Rogue in metal form without harm in a subplot that was never spoken of again (namely because Claremont was punted from UXM for a few years after that), faded into background for some more time, and then was sacrificed to end the Legacy Virus subplot in about the most ******ed method possible. For those not aware, the gist was that after X number of years, Beast had finally concocted a cure for the virus, the only catch was that it only "activated" after it had been injected into a mutant, and said mutant would die to provide the antibodies. But that wasn't enough. After Colossus injects himself with the virus, supposedly him activating his powers as he died for a moment spread the cure into the sky and allowed it to cure mutants worldwide...despite the fact that Piotr injected himself in the lower basements of the X-Mansion. Hey, it's only comic books, right?
After a few years of death, Joss Whedon revives him in AXM, and he beats Ord (the same guy who lost to Lockheed). Despite being a Maguffin character for the finale of Whedon's run, Colossus does little besides be Kitty's rather boring boyfriend. In interviews with WIZARD, Whedon admits to being a bit perplexed with how to write Colossus, perhaps because he spent an entire career on BUFFY/ANGEL writing male characters who were anti-heroes or downright reformed villains. This is perhaps the pinnacle Colossus has gotten in terms of character focus in this decade. Ellis immediately punted him from the roster when he took over. Colossus then returned to his usual background spot in Fraction's "cast of hundreds" X-Men book, moping about Illyana (whether she's dead, alive, evil, possessed, etc.) and naturally moping about Kitty being dead. Then Magneto brings her back, and now he's moping about her being trapped in ghost form (because that never happened before and she was never totally cured of it during the Morlock Massacre). Atop this, he has two cameos in two X-Men films and in terms of animation has been virtually ignored since the 90's, and even that show only gave him two episodes (they were just good ones). WOLVERINE AND THE X-MEN even had the audacity to heavily feature Colossus in promotional images for the premiere of the show and even in the first DVD release despite the fact that he only shows up for a few minutes in the first episode, and Mystique assumes his form in I believe episode 7 or 8, and that's about it. He's barely mentioned and none of the X-Men miss him, despite the fact that Wolverine is able to reassemble the ENTIRE roster but Colossus. He was talked up for the second season that never happened, but that's like a promise that wasn't kept. Which wouldn't get my goat as much except these were the same writers who worked on X-MEN EVOLUTION, in which Colossus appeared in about 7-8 episodes yet did astonishingly little in that time frame, who claimed they "would have focused on him had they gotten a 5th season" despite the fact that they chose to spend their final season pointlessly introducing one-off, never-to-return characters like Legion and Mirage (and naturally shoving X-23 at the viewer). As such, I would not be surprised if an entire generation of X-Men fans doesn't know Colossus from ****ing Sunfire or Changeling. You'd need to be at least 20-21 to even vaguely recall him doing something cool somewhere.
It all comes down to writing. After Claremont left the X-Men franchise in 1991, few writers really knew how to handle a character not known for being an anti-hero in a franchise that, by '91, was ruled by them (Wolverine, Cable, Gambit, Bishop, even Rogue to a degree). Some blame the end of the Cold War as a reason why a "noble Russian" was no longer considered innovative, but that's no excuse; Iron Man and the Fantastic Four had no end of topically related Cold War era stories and villains, and all of that wasn't abandoned. On top of that, for a character who for the longest time was considered about as strong as the Thing, he had few impressive victories for a "tanker" and tended to get his rear handed to him whenever it really counted. The fact that anyone looking for awesome Colossus moments has to go back to the 70's when he killed Proteus speaks for itself. The problem has been passed around since then and hasn't improved. Beast at least spent a lot of time in the Avengers to be appreciated elsewhere, and even Kitty and Nightcrawler spent about a decade involved with Excalibur (Colossus joined them, but towards the end of the volume). Nightcrawler even led Excalibur at one point.
Nightcrawler had suffered that "fade into the background" dilemma for the last few years, but Colossus has been plagued by it for as long as some fans have been reading, or even since they were born. I'm not saying the metal man can support 4 ongoing titles, or even a mini, but for heaven's sake can't he get consistent characterization or cool moments on some team books? There are literal buckets of wasted potential if one goes back into his history and sees some of the stories that were never followed up on, or handled properly. And he at least has a distinctive design. How bad is it? The X-Men used to be based in New York, not far from Manhattan, THE art capital of the world, and the only time Piotr's artistic skills were utilized using that backdrop was when he had amnesia. Colossus easily could have had a PLANET HULK style subplot with Breakworld that has gone nowhere. Does anyone remember that technically Nightcrawler showed him how to use a sword? Can he still touch Rogue in metal form safely? Can't Dr. Strange just fix Kitty in a half hour? Given how well Alicia Masters' sculpting talent has been utilized in stories or details over the years, it's almost appalling the lack of imagination generations of writers have around a tanker mutant who paints (well enough that, with amnesia, he made his living selling paintings). I could probably go on and on for another few thousand words, but I think I made my point. If I had the time and the drive I've been tempted to return to fan fiction just to show how it should be ****ing done. It's not Alan Moore level hard, Marvel.
The Shroud has always been a low level character I liked, and I am glad to see him in SHADOWLAND: BLOOD ON THE STREETS, as well as his tenure dating Arachne. My only quibble is that in Mighty Marvel fashion, his most interesting gimmick has mostly been abandoned. Look at his origin, and he's very much an outright riff on both Batman and the Shadow. His gimmick from the 80's was that Shroud pretended to be a gang leader/villain, while secretly undermining crime from within. Executed properly, this could make for a very unique and interesting character, maybe not for his own series, but to interact with many other characters, from street heroes to the Avengers. Instead? After the Night Shift figured out his intentions, he's basically been operating as Batman Lite ever since, only in Marvel that makes him Moon Knight Lite. Only Marvel is so clueless as to eliminate a character's most unique plot point for about 15-20 years and then wonder why no one recalls them.
Stingray is there too, and one could make a major case for The Slingers, especially Dusk (who has done the least out of all them, even Hornet). I could argue a slew of characters created after 1997 have had the **** kicked out of them or been mostly abandoned. Machine Teen, a new character who is a teenage robot, is the sort of idea you would think no end of writers should have a ball with to fill out a team roster spot, yet I imagine none on staff know who he is.