I recently happened upon a really cool site that makes it really easy to catch up on just about every TF cartoon ever made. What's even better is that it uses YouTube as one of its primary media players (the other player is also very good, being lightweight and mobile supported). The ads on the sides of each page can even be closed off, making the videos play even better!
The TransformersNote that these episodes are listed here in production order, meaning that "The Gambler" is separated from "Child's Play" (when "The Gambler" takes place immediately after "Child's Play), and "Aerial Assault" is out of chronological order (it should come after "The Revenge of Bruticus"). Also, the version of "Dark Awakening" featured here is the original ending version, rather than the second ending version that teases "The Return of Optimus Prime".The Transformers: The MovieTransformers: The Headmasters
Japanese w/ English SubsTerrible English DubTransformers: ChÅjin Masterforce (sub)
Note that "The Big Book of Masterforce" listed beneath episode 1 is meant to be viewed after the final episode.Transformers: Victory (sub)
Beast Wars: TransformersBeast Machines: TransformersTransformers: Car Robots (sub)
Transformers: Robots in Disguise (2001)Alternate linkTransformers: ArmadaAlternate linkTransformers: Super Link (sub)
Transformers: Super Link - Special Episode (sub)
Transformers: EnergonTransformers: Galaxy Force (sub)
Transformers: CybertronTransformers Animated
Season 1Season 2Season 3Transformers: Prime
Season 1Season 2Season 3Predacons RisingTransformers: Rescue Bots
Season 1Season 2Note that "Spellbound" and "A Virtual Disaster" are swapped here.
"A Virtual Disaster" is supposed to come before "Spellbound".Season 3Note that "Season 03 Episode 9" and "Season 03 Episode 12" are actually episodes 20 and 22 of season 2.
They are supposed to come right before and right after the season 2 episode titled "Movers and Shakers".Transformers: Robots in Disguise (2015)Of course, this isn't every TF cartoon. Some things like Scramble City, Zone, Micron Densetsu, RobotMasters episode 2, Sanjou Gattai Transformers Go!, and the terrible English dubs of Masterforce and Victory are all missing.
Though, as a bonus, there's also...
Challenge of the GoBotsGoBots: Battle of the Rock LordsMachine Robo: Revenge of ChronosRobotixG.I. Joe: A Real American Hero
A Real American Hero mini-seriesThe Revenge of Cobra mini-seriesSunbow cartoonG.I. Joe: The MovieDiC cartoonJemInhumanoidsC.O.P.S.M.A.S.K.And a whole host of other cartoons and anime, current and classic!
