Mobile Suit Gundam ZZ was supposed to have Char but that was cancelled when Char's Counterattack was given the green light. Instead they got Glemmy Toto, a blonde, charming 17-year old, who has all of Char's manipulative ability and piloting skill, serves as a rival to two of the main characters, and eventually sets himself up as a rival to the Big Bad. He also seems to have Char's predilection for younger girls, although given his own age, that's hard to tell.
Gundam Unicorn has Full Frontal, who (despite the unfortunate name) is the Chariest Char since Char himself, being a cyber-newtype genetically altered to look like Char, with Char's memories implanted in him via the psycoframe; to drive the homage even further, he is voiced by the same actor. Subverted? Or played ultra-straight? You decide.
In the novels, Frontal is definitely a clone. But the anime has left it more open to interpretation, he may in fact be the real Char and simply subject to some accusatory 'you sold out' comments from Mineva.
Gundam Wing has Zechs Merquise/Milliardo Peacecraft, who combines all three Char-styles. Somewhat justified, since Wing has been described as "UC Gundam from MSG to CCA compressed into one series", though Zechs switches the sequence of Big Bad and The Mentor aspects compared to the one on the original Char.
Gundam X has The Captain Jamil Neate taking on The Mentor aspect (complete with shades and sideburns). A more direct example comes from Lancerow Dawell, who is a sort of Alternate Universe version of Char. The backstory of Gundam X involves a much more devastating version of UC's One Year War (culminating in a successfulColony Drop), in which Lancerow played the role of The Rival-Char and Jamil played the role of Amuro.
Mu La Flaga himself fits the Zeta style Big Brother Mentor type, particularly to the main character; he does however start with an Ace Custom mobile armor instead of a mobile suit, before receiving Kira's Strike.
Finally, in both SEED and the first-half of SEED Destiny, Athrun Zala serves as Kira's rival (complete with a red Gundam, instead of as simple Ace Custom) before his Heel-Face Turn. On a side note, Athrun's name is Arabic, derived from the Greek word, "erythron", meaning "red".
Neo Roanoke (actually the Not Quite Dead Mu la Flaga) fills the role of The Rival, while Athrun acts as The Mentor to Shinn, at least in the beginning. Then they swap, both of them (re)joining Kira. Neo/Mu loses the mask, gets the golden mobile suit and acts as the Older and Wiser figure to Kira and Athrun, while Athrun gets yet another red MS and ends up as The Rival to Shinn.
Gundam 00 has Graham Aker, who starts as a more general example of The Ace and The Rival, challenging the Gundams with lesser mobile suits like the Flag, but is upgraded to a full-blown Char Clone in the second season, where he gains a Char-scar and puts on a Cool Mask. He also takes on a new name ("Mr. Bushido")...though it turns out that it's just a nickname other pilots gave him for his increasingly samurai-like tendencies, and he went with it. Like so much in 00, he's a bit of a deconstruction: He doesn't wear the mask to hide his identity, but rather because of scars given to him by the ostensible hero of the series.
Model Suit Gunpla Builders Beginning G reveals Boris Schauer. Because the story takes place in the real world, Boris may just be a Char fanboy. Nevertheless, his similarity to Char is more than just cosmetic, as no ordinary fanboy will ride a Cool Horse just to mimic Char.
Gundam AGE has Vagan Ace Pilot Zeheart Galette. His mask manages his Psychic Powers, which are powerful enough to require a custom (red) suit that is 3 times faster than normal Vagan suits. Although he isn't related by blood to any of the heroes, he is Asemu Asuno's former best friend and becomes The Rival. He never had interaction with Kio in the third arc, not counting their bouts in their mobile suits.
On the Quattro side of things, we have the 3rd Generation's Federation mobile suit team leader Seric Abis.
Before the release of Gundam Unicorn, a probably out of continuity novel called Gaia Gear, which took place a few centuries after Mobile Suit Gundam, featured the main character Afranshia Char - a literal clone of the original Red Comet.
Gundam Build Fighters has the Student Council President Tatsuya Yuuki as the closest character to the Trope. He's nicknamed the Crimson Comet, and pilots the Zaku Amazing, (a highly customized Zaku II Char Custom); he only falls short for want of blonde hair and a mask. By episode 5, we also learned that he's up to something more than just Gunpla Battle.
Aura Battler Dunbine: Bern Bunnings from this show is an obvious Char. Rival status, fake moniker, wears a mask, extreme respect from his underlings, and grudging respect from his superiors.
Bakugan: Spectra Phantom wears mostly red (including a mask), is blonde, is The Rival, and is actually named Keith Clay, the older brother of Mira Clay. Also, Masquerade doesn't have a thing for red nor does he err, she have a younger sister, but he is mostly this trope.
Emperor Barodius and Dharakinoid in Gundalian Invaders are Chars of themselves in Mechtogan Surge, now Mag Mel and Razenoid. They've been so warped by evil, they've cast off their old identities.
Though just a minor character, it's obvious whoFindor◊ in Bleach is modeled on. Also his name vaguely sounds like one of Char's made-up cover names.
The Big O: Schwartzwald. A masked character with his own agenda, consistent rival to the lead, pilots three red mechs, and they are more maneuverable (three times faster).
Brave Raideen: Actually a reverse of this trope; the character Prince Sharkin is who Char Aznable was modeled after. For all intents and purposes, however, it can also qualify.
Code Geass: Split between the show's main character, Lelouch, who gets most of Char's backstory (estranged son of nobility, works under a fake name and wears a mask, has a younger sister who doesn't realize who he is, seeks revenge for his parent's murder), and Kallen, who gets his action role (Ace Pilot with speedy red mecha, The Rival of Suzaku on the battlefield). Also worth a mention, is that Word of God indicates Lelouch was initially going to be a white-haired pretty boy, and thus would have looked the part even more. In fact, co-creator and head writer Ichiro Okouchi himself said that Zero was designed specifically to wear a mask because he felt that it wouldn't be a Sunrise show otherwise!
Dancougar Nova: A masked blonde woman who pilots the red mecha R-Daigun against Dancougar. She turns out to be the Idol Singer Eida.
GaoGaiGar: Soldat J is blond, wears a face obscuring helmet, is rival to main character, is faster than the main character on foot and in his smaller mecha, and is incredibly popular.
Gear Fighter Dendoh has Altair (the mask-wearing bad guy), who is the brother of one of the main characters and The Rival of the protagonists (though not by choice). He also uses a palette-swap of Dendoh, the Knight Gear Ogre.
Vega resembles Char in his Quattro phase: she's a mysterious mentor with blonde hair and a mask. Also, she is secretly the mother of one of Dendoh's pilots and Altair's sister.
Full Metal Panic! has a Char homage in a first season filler episode, where the man in question is the leader of a Jerk Jock team of mecha pilots. This ended up getting Lost in Translationnote whether by accident or intentionally to avoid lawsuits is unknown, but if you know what to look for it's blatantly obvious.
Isekai No Seikishi Monogatari: Dagmyer. Handsome blonde who wears a mask in the first episode, inspiring leader and idealist fighting against the system, Manipulative Bastard... he hits most of the criteria for both original recipe and Counterattack-era Char, except that he uses a blue Seikishin. And that he's hopelessly outmatched by his rival, Kenshi.
Lyrical Nanoha: Nanoha's basically a Gundam disguised as a magical girl, so is it any wonder her first-season rival Fate is a blonde whose fighting style is geared for speed? Especially when she gets Sonic Form in A's, which makes her three times faster!
Metal Armor Dragonar: Meio Plato, the Ace Pilot rival with the nickname Blue Hawk, his character design resembles CCA Char, his sister is a major character on the protagonists' side, and he has his own Ace Custom Metal Armor.
In Naruto: The Big Bads Pein/Nagato and Tobi/Obito takes on this trope as both characters conceal their identities as well as having features with similar colors before changing throughout the story. Their intentions later on takes on CCA style of events making them Well-Intentioned Extremist and Man Behind the Man from the scenes.
In Sands of Destruction based on a video game of the same name the Char clone is a black teddy bear with an Eyepatch of Power and red bandanna, voiced by the original Char. To top it off, he is a friend turned rival to another teddy bear Toppi, who is voiced by the original Amuro.
The Five Star Stories: Vralgo "Testarossa" Kentauri is definitely a Char, even wearing a mask (and a fake beard, of all things) while posing as the mercenary knight "Boowray Red". Unlike most Char clones, he only lasts a single story arc before his final battle with his own arch-rival, King Colus, comes to a mutually fatal conclusion similar to the original's. Interestingly his and Colus' descendants become allies in a later story arc.
Zoids: New Century has Naomi Fluegel, who pilots an Ace Custom red Gunsniper, and is even called the Red Comet in-universe. Her Leitmotif is even titled "Here Comes the Red Comet!", a reference to the original Char's theme song, "Here Comes Char!".
Leon Tauros also pilots a custom Red Blade Liger, and is the older brother of Leena, one of the regulars.
Zoids Genesis: Zairin of Zaltz is quite the Zoid prodigy. He seems to be quite a familiar character, no?
Also from the Golden Age arc, we have Samson Corbowitz, who is specifically mentioned to have armour three times THICKER than normal and is a (very brief) antagonist to Guts and Caska.
Infinite Stratos has Charlotte Dunois, the pilot of an orange-coloured Ace Custom IS under the disguise of a guy named Charles. Before the gender reveal, she served briefly as The Mentor of sorts to Ichika; after the reveal though, she immediately became The Rival to the viewpoint of the other main female characters.
For a series that isn't about Humongous Mecha, Yakitate!! Japan has "Meister" Kirisaki, a blond mask-wearing Ace Baker whose sister is a member of the supporting cast. He also plays a Zeta-style role as Azuma's mentor. The connection then progressed to Hilarious in Hindsight territory when the anime version was eventually picked up by Sunrise.
Anyone watching Ozuma will see a particularly familiar figure. Gido Gairaa is an aloof villain-like character with a white mask who can be summed up as the bastard child of Harlock and Char Aznable.
Hiro from Beyblade is a Char clone: he wore a mask at the start and switched to shades by the end; he played The Mentor to the protagonist (who is his little brother) and later to Brooklyn; his bit-beast Metal Driger is basically an Ace Custom of the original Driger.
Subaru Okiya of Detective Conan is a Char clone...he's blonde (at least for his keyhole), he drives a red car (white in some instances) with suicide doors, he wears glasses and squints most of the time and his Long Lost Relative is Masumi Sera. Considering he's actually Shuichi Akai...
South Korean Animation
Space Thunder Kids' Space Black Knight is Char Aznable in a black costume. In fact, most the cast are recoloured Gundam characters.
The Gundam spin-off RPG MS Saga introduces Captain Hal Vizardt. He hits all the Char high notes: blonde, masked, ace pilot, acts as a mentor to The Hero, pilots red MS (for extra points, he specifically pilots Char's), and is secretly the older brother of another party member in disguise.
Mega Man Classic: It wouldn't be much of a stretch at all to assume Proto Man was a Char.
Dynamo from X5 is also built up as such, particularly the old-fashioned MSG-style rival (although he's more of a Friendly Enemy). He wears black instead of red, but otherwise exhibits most of the traits associated with Char clones. He has the white hair, a visor on his helmet that covers his eyes, and is even said to have skills equaling or perhaps surpassing that of a Special A Class Hunter note X and Zero are respectively B and Special A . Despite possessing abilities similar to X and Zero's combined skillset, his threat level diminishes throughout X5, as he's soundly defeated by X/Zero twice and retreats each time. By the time of X6, Dynamo is considered little more than a nuisance by the Maverick Hunters; that being said, he's still smart enough to knowwhen to call it quits.
Done again with Sleigh Presty, who pilots a high-speed red mech and gains the nickname of the "Scarlet Comet." The characters were actually going to call her something starting with "Re-", but one of them breaks the fourth wall to stop them, saying they'll be sued. And once again, you can have her face off against the real "Red Comet" in her debut game.
Kyosuke Nanbu. Pilots a red, horned mech? Check. Acts as The Rival (From another point of view) and The Mentor? Check. Has blonde hair? Semi-checked. Lampshaded in one of the 4koma's where Quattro confronts Kyosuke that the blonde bangs at the tip of his hair are actually a fail attempt to dye his hair blonde so that he can become a complete Char Clone.
Super Robot Wars W gives us Applicant, who wears a mask, commands a red battleship, and is the main character's father reborn in android form. In-story, he is considered one of the most dangerous enemies you ever face.
Notable: Camus himself is a clone target... a "Camus" is, while only Eldigan and Ares retain being direct Char clones (albeit, maskless Char clones), a recurring archetype for anti-villain characters. They typically fall under "My Country, Right or Wrong", and sadly are usually killed off.
BlazBlue: Relius Clover fights with a red robot who is really Carl Clover's mother, wears a mask that resembles The Phantom of the Opera, is blonde, is The Rival to his son, Carl, is co-Dragon to the Imperator Librarius (alongside Hazama/Terumi). Yep. Relius is definitely a Char.
Chrono Phantasma took this even further by having a Palette Swap of his that's a reference to the original Char. note Either him, or Full Frontal.
MOTHER 3: The masked man is a dead ringer for Char.
Dynasty Warriors: Gundam series features several Char clones, as well as Char himself. The original, if memory serves, only has Char and Milliardo. The Sequel adds more of Char himself and adds Athrun. #3 adds Full Frontal and Shwartz Bruder to the player's options, and features Milliardo and Char fighting on the same side. Mr. Bushido is available as DLC.
Lampshaded by Duo Maxwell in the third game upon meeting Full Frontal.
"How many people with goofy masks could there possibly be?"
Yasha from Asura's Wrath has a bit of this going for him, with a cool personality, a mask of sorts and overall has more speed, skill and precision based combat to be a counterpart for Asura's raw power and strength. The color scheme is blue instead of red, to compliment him being the Blue Oni to Asura's Red Oni.
Plus, Durga, Asura's (dead) wife, is his sister, making him Asura's brother-in-law.
Gai, the Big Bad of Bangai-O, has a few of these traits. He pilots a robot similar to the title one (with red wings added onto it, for good measure), not only sharing the same abilities, but also able to activate temporary invincibility at will. He is also somewhat calmer than Riki. On top of all that, the ending reveals Gai to be the long-lost brother of Ban, Riki's father. Which makes him Riki's uncle!
Doujin game Super Cosplay War Ultra has Masa, who cosplays as the Red Comet and uses Char's voice clips (his theme song is also Char's theme from one of the Super Robot Wars games). He also fits the Ace Custom trope by being a more powerful version of one of the standard Mook types that cosplay as Zakus (the mobile suit type from which the Red Comet was derived from).
Armored Core has Nineball/Hustler One, the highest ranking person in the arena. His AC is red and is better than you in every way. This is mostly because he's an AI, and when he reveals this, he gets an Ace Custom. He is so iconic in the Armored Core fanbase that every game after his initial appearance either uses him for The Cameo or has an Expy of him.
Ash Crimson is an odd example of this archetype in that he embodies the traits of all three variations of Char at once. He wears red, sports platinum-blond hair, essentially upstages the entire collective cast at every turn (no, really), and schemes to steal the powers of the ThreeSacred Treasures (Kyo, Iori, and Chizuru; he succeeds in depowering the latter two). He's set up as a Hidden AgendaVillain Protagonist, but is shown to be a Well-Intentioned Extremist, working to counter-act his time-hopping Identical Ancestor in order to keep his best friend/older sister figure/rival Elisabeth safe.
Raiden could qualify when his visor down in Revengeance.
In Steambot Chronicles, Elder the White Phantom is the reigning trotmobile champion, with a trotmobile that is way more powerful than anything else in the game. He wears a white mask to hide his identity. He is also the leader of the Bloody Mantis, the terrorist organization that is trying to destroy modern society, and a former member of the band you joined, whose little brother was also a band member before he was killed.
Operator: Just about the only named enemy character is blond-haired Humongous Mecha ace Jaeger, who incidentally wears red and seems to exist purely to fight the main character one-on-one.
MegasXLR: Evil Coop from the show's series finale. His Mecha #14 had a strong resemblance to Char's Sazabi, while his army resemble Zakus (and of course, as Coop, he's blonde).
Matt Trakker, the lead hero of M.A.S.K., is blonde, wears a mask, and drives a red transforming vehicle.