For anime during the 1990s in the West, it was a time of resource scarcity. Every scrap of anime was hungrily consumed. In the late 90s, television anime blocks started appearing more often, exposing a new generation to the medium. No one can be blamed back then for shows becoming too popular and labeled as classics, nor for shows going overlooked. But it's 2020 now, and every 90s anime can be at your fingertips instantaneously.
Also, please understand, with a designation of "Too Popular", feelings might get hurt. Some anime are objectively not that good, but because of their immense popularity, they're more open to scrutiny.
10 Overlooked: Outlaw Star (1998)
More than just about any anime that aired on Toonami/Adult Swim, Outlaw Star feels like it's fallen out of favor the most. This show shouldn't be saddled in mediocrity but heralded amongst the same stars that Gene Starwind and his crew fly through.
Its closest comparison is likely Cowboy Bebop since this is also a gritty space western and opera. Except in Outlaw Star, some guns can shoot magic bullets called Caster Shells—some can create black holes. If you enjoyed Cowboy Bebop, then Outlaw Star is its worthy peer. This anime does not deserve to become a footnote in anime history—it's far too good for that.
9 Too Popular: Gundam Wing (1995)
It's also thanks to Toonami that shows like Gundam Wing grew to be more popular than they should have been. Compared to other entries in the Gundam series, this is extra melodramatic and borderline psychotic. Who else remembers in Episode 1 when Relena invites Heero to her birthday party and he responds with, "I'll kill you"?
It is not an easy rewatch and the era of binge-watching has done it no favors. Much like Dragon Ball Z, it plods along and is in serious need of editing. So, while this series did give Wing Zero and Endless Waltz to the anime world, a better Gundam show should have taken the spotlight from this series. And speaking of which...
8 Overlooked: Mobile Suit Gundam: The 08th MS Team (1996)
The 08th MS Team premiered right in the middle of Gundam Wing, almost as if it was trying to be a palate cleanser. If you weren't a fan of the gloom and melodrama that came with Gundam Wing, then The 08th was likely what you were seeking. This series aimed for a more mature tone and to be more grounded in reality with its action and mobile suits.
There was also a nice little wrinkle with the characters being regular soldiers in the war—no prodigies, no psychopaths, no high-ranking generals. The action scenes are masterfully crafted, building tension with visuals and sound—something as easy as not seeing the pilot's face but hearing their quickened breathing is incredibly effective. This series is well worth a watch even if you aren't entrenched in the Gundam universe.
7 Too Popular: Digimon: Digital Monsters (1999)
When's the last time anyone watched Episode 1 of Digimon? The animation is beyond brutal—it's inconceivable how it didn't bother anyone.
While Digimon never reached the heights of its Pokémon brethren—even though it's substantially better—it did enjoy a lengthy stay in the anime spotlight. And because of its immense popularity, it ended up overstaying its welcome. Digimon spawned two more lengthy series and five spin-off series. Digimon: The Movie was a disaster due to the attempted cramming of three Digimon movies together—and there are still six more films after that. Plus, there's another film and a series reboot coming next year.
6 Overlooked: Blue Gender (1999)
Toonami killed Blue Gender inadvertently. Originally, Blue Gender was to air on Toonami, so it was edited for that block; however, Toonami passed the show to Adult Swim but left in all the edits.
What's behind those edits is a mature and powerful tale of humanity on the brink of the apocalypse. The world is under attack from these alien insects called "Blues" who contain a virus that is wiping out the population. Most people have secured safety on Second Earth. We follow Yuji and Marlene as they attempt to reach Second Earth and their military struggles on the way there.
5 Too Popular: Tenchi Muyo! (1992)
The Tenchi Muyo franchise is a permanent fixture upon the "Harem Mount Rushmore". There's no denying how influential this was to the genre and how entertaining the show was. But due to its immense success, the Tenchi Muyo franchise morphed into a monster that has not stopped to this day.
The original six-episode, 1992 OVA morphed into three more OVA series (with another one coming this year), four anime series, three movies, and five spin-off series. Twenty-eight years is an impressive amount of time for anything, but maybe it's time to let the Tenchi harem go.
4 Overlooked: Samurai X: Trust & Betrayal (1999)
If you don't recognize the name, Samurai X is also known as Ruroni Kenshin. And if you didn't know, Trust & Betrayal is one of the greatest anime to have ever existed. This four-episode, two-hour OVA examines Kenshin's origin; how he got his scar, his indoctrination into the Mitsurugi Ryu sword style, his life as an assassin, and what made him vow to never kill again.
This OVA is dark, bloody, and violent. The comical whimsy the anime had is gone, and it's for the better. It is a beautiful, haunting tale, and is brilliant to watch even if you haven't seen Ruroni Kenshin.
3 Too Popular: Most Dragon Ball Z Films (1990-1995)
While most of its run was in the 90s, Dragon Ball Z, started in 1989—thus making it an 80s anime; however, most of its movies were released in the 90s. Between March 1990 and July 1995, Toei Animation pumped out 12 movies (and, for what it's worth, 231 episodes of Dragon Ball Z and two TV specials).
Most of these movies were watched simply because they bore the name of Dragon Ball Z. There is simply no reason to watch Lord Slug, Super Android 13, Broly — Second Coming, or Bio Broly. And yet on MAL, each of those movies has more scores than Outlaw Star. It's just not right.
2 Overlooked: Great Teacher Onizuka (GTO) (1999)
It's only been in recent years that GTO is receiving the acclaim in the West that it should have been receiving all along. You see, Onizuka is a somewhat reformed former bike gang leader. His new goal in life is to become the greatest teacher ever. His path looks dubious however due to stern school officials and delinquent students who want nothing more than to get him out of the classroom. But that won't keep him from trying to accomplish his goal—even if he has to skirt the rules to do so.
This gut-busting comedy and action-packed anime will teach you one thing—Onizuka is a badass. And to put the icing on the cake, the person who is dubbing this effortlessly cool badass? Steve Blum. It literally could not get any better.
1 Too Popular: Pokémon (1997)
Well. Time to put on the boxing gloves...
Pokémon is terrible. Downright awful. One of the worst adaptations of any video game ever. Ash Ketchum is one of the worst Pokémon trainers to have ever lived. In terms of trainers, he's on the level of Bug Catchers. Seriously though. How many times does the theme song say "Gotta catch 'em all"? Ash catches 11 Pokémon in this original series, and that is being VERY generous with the word "catch".
Furthermore, he legitimately beats three out of eight gym leaders and is gifted the other five badges. It's no wonder it took him 20+ years to finally win a league—he isn't a good trainer. This anime does not embody what made the video games so popular, and it's only because of those games and Pokémon cards that this anime succeeded at all. Go watch Pokémon Origins instead—it accomplishes more in six episodes than Ash has in over 20 years.