These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: Rampage. Is he a twisted, sinister monster, or a tortured, tormented misfit? "Both" is an option, but between the other two options, there was a voice for each... and there still will be if you bring up the topic in the right place.
Broken Base: There are a few individual episodes that have divided fans.
"The Low Road". Some found it to be an entertaining comedy episode while others have found its toilet humor to be tasteless. Either ways, the reception for this episode was not 100 percent positive.
"Optimal Situation". A decent action-packed Season 3 opener or an anti-climactic finish to "The Agenda" trilogy, and the beginning of the end where the show become more toy-oriented?
"Go With the Flow". A comedy episode where the protohuman children play a big role. Some fans found it an enjoyable romp while others felt it was a pointless filler episode that took the place of "Dark Glass".
The "Nemesis" two-parter. Opinions over the finale have also differed. You have fans who feel that it was a good finale where the stakes were high, the tone was epic, and the war became more real than ever. On the other hand, there are other fans who felt the series finale went overboard in killing off more then half the cast. And considering a lot of those deceased characters had their fair share of fans, you can bet at least somebody's going to be angry at how their favorite character was brutally killed off.
Megatron is a self-proclaimed tyrant and would-be Galactic Conqueror, who named himself after his world's equivalent of The Antichrist. A user and abuser of his followers, Megatron divides the world into enemies and pawns, killing or enslaving the former, and ruthlessly exploiting the latter. A gloating sadist, Megatron never kills anyone quickly when prolonged torture will do, considers his own allies expendable, and hopes to bring Cybertron, and eventually the galaxy, under his heel. His more notable crimes include: extracting half of Rampage's spark, placing it in a vise, and using it to torture Rampage into submission; ordering Dinobot to kill Quickstrike, one of Megatron's more loyal soldiers (though this is a relative term), after Quickstrike lost to Dinobot in a sort of re-entrance exam into the Predacons (Dinobot refused); an aborted genocide of humanity's common ancestor; attempting to rewrite all of his history by killing the original Optimus Prime; and finally, sacrificing all his remaining troops in order to gain control of the Nemesis and set out to overrun the galaxy. His defeat doesn't stop him either - when he returns in Beast Machines he's gotten worse, picking up a serious god complex along the way. Seizing control of Cybertron, Megatron extracts the sparks from everyone on the planet, reducing them to mindless drones. Accquiring a hatred of all organic life, Megatron tries to scrub Cybertron clean of it, resulting in the near destruction of all life, robotic and organic, on his home planet when his last mad grasp for power finally fails.
Tarantulas is Megatron's Evil Genius, and a schemer and backstabber second to none. Planted as The Mole in Megatron's operation by the Predacon Secret Police, Tarantulas is a cackling Mad Scientist, who enjoys performing gruesome experiments on his victims, and eating anything or anyone he catches in his giant webs - it doesn't matter whether it's organic or robotic, he admits to enjoying the act itself more than the meal. He brainwashes several Maximal protoforms into becoming Predacons, most notably Blackarachnia and Inferno, and eventually reveals that he hopes to usurp control of the team from Megatron. That's all in Season 1. Tarantulas only gets worse after this. He exploits and Mind Rapes Blackarachnia, leaving her with a paranoid terror of him, and later swears a vendetta against her, promising to hunt the other spider down and kill her for daring to defy him (if this sounds suspiciously like Domestic Abuse, it should). He tries to destroy The Ark, which would have lead to Unicrondevouring Cybertron in the future, and the extinction of the Transformers as a species. Ultimately betraying both sides, Tarantulas is revealed as the spawn of Unicron, and attempts to use alien technology to wipe out Autobot, Decepticon, Predacon, and Maximal alike, swearing that when he's done with his own species, he will return and commit genocide against the aliens themselves. Void of loyalty or conscience, Tarantulas makes even his own nominal allies uneasy, a fact that he is downright proud of.
All five characters voiced by Scott McNeil have received this treatment to various degrees. Two however, deserve special mentions.
Waspinator. When the series started, he was a semi-skilled fighter that only stood out because of his unique speech patterns. The writers generally disliked him, but were required to use him, so they purposefully made him the Butt Monkey of the series. This comedic take struck a chord with fans and the writers soon warmed up to the character, as well. Waspinator was to be offed in the second season to make room for new characters, but was spared due to his popularity. He gets the last line in the show and even makes it to the end of the sequel series Beast Machines. To top it off, he was the second BW cast member to appear in the Transformers Hall of Fame.
Dinobot, largely because of his Heroic Sacrifice. Evident when many years later, he emerged as the first member of the Transformers Hall of Fame. He beat out Generation 1 favourite Soundwave for the spot!
Of the toy-only characters who didn't make it into the show, Razorbeast is quite popular with fans. This is largely due to Simon Furman's usage of him in IDW's Beast Wars comics, where he's portrayed as a snarky and stern yet kind-hearted Guile Hero.
Even Better Sequel: There are quite a few fans who hold the opinion that Beast Wars is the best Transformers series yet made, as stated above. In fact, Beast Wars is one of the few Transformers incarnations not to be heavily criticized by the Generation 1 purists. It's arguably gotten to the point where Beast Wars has done a sort of stealth Adaptation Displacement to Generation 1. Many of the traits self-proclaimed Transformers purists proclaim they wanted out of the movies (little-to-no humans, just lots of action of robots beating each other up) were from Beast Wars, whereas the movies were actually much closer to Generation 1 in their level of involving humans and the amount of action.
Blackarachnia asks, "What is it with guys and explosives?" Later, an infamous film director would come to echo this sentiment and utilize it in the Transformers franchise.
In his very last words of the entire series, Rattrap muses with a smirk, "And you know what the best part is? We don't have to see Megatron's ugly butt again 'till we get back to Cybertron!" How right you are, Rattrap. How right you are.
Genius Bonus: Loads. The writers and animators at Mainframe were clearly very well-read. Dinobot's many Shakespeare allusions are a good example.
Growing the Beard: Season 1 gradually grew higher in quality until the season finale where the series really took off.
Harsher in Hindsight: Rampage laughing as he died and allowing Depth Charge to kill him is kind of cringeworthy after the death of his voice actor Campbell Lane on 30th January 2014.
Heartwarming In Hindsight: During the original Dinobot's death, Optimus states "May his Spark join the Matrix, the greatest of Cybertron." In 2010 came the Transformers "Hall of Fame" where, every year, Hasbro began honouring fictional characters (one of which was fan-voted) and real people associated with the franchise. That year, Dinobot was intended as a joke candidate since the idea of him beating out Generation One veterans like Soundwave, Grimlock, Jazz and Shockwave was seen as inconceivable. Guess who the fans voted for that year?
Also heartwarming in that Dinobot was a Predacon, a decendant of the Decepticons. If just one of them could learn the value of honor and a simple human life, then maybe there's hope for the rest of them?
Hilarious in Hindsight: Megatron's frequent annoyance with the ever-devoted Inferno arguably becomes even funnier with the knowledge that the former's voice actor David Kaye took on the role of Lugnut. If that's not enough, at one point Beast Wars Megatron asks (rhetorically) of his troops, "Eager to begin another glorious Predacon day are we?"
When the series first premiered, there was the cry of "TRUKK NOT MUNKY!" from detractors. In season 3's premiere episode "Optimal Situation", as Optimus shares the spark of Optimus Prime, he turns into a new transformer whose modes include truck and monkey (gorilla).
HSQ: Extremely high during the season finales and two-parters.
Ho Yay: Rattrap and Dinobot's whole thing has inspired many a slashfic. Cheetor's fawning over 'Big Bot' (Optimus) is sometimes interpreted as more than admiration and has given way to several slashfic.
Jerkass Woobie: Dinobot, Blackarachnia and, to a much lesser degree, Rampage.
"Beast Mode" is now a popular phrase amongst many people in times of intensity.
Moral Event Horizon: Megatron crosses it several times: he planned from the beginning to wipe out an entire timeline's worth of Transformers and other lifeforms; in the episode "Code of Hero", where he attempts genocide against defenseless proto-humans; and in the series finale.
For Dinobot II, who had recently gained access to his namesakes' code of honor, Megatron crossed the line when he decided to use capital scale weaponry on a single proto-human.
Tarantulas crosses this when He attempts to blow up the Ark, which would have wiped out all the Autobots, Decepticons and their descendants. It's also implied that he did this so that his master Unicron would be able to destroy Cybertron without difficulty.
Narm: Working in the exceedingly cheesy names into character's introductions, as well as Optimus Primal's Title Drop (seen as the page quote on the main page).
A more specific example from an early season 2 episode has the newly transmetal Megatron articulating how the Beast Wars have changed... while skating around the room on his new feet wheels as if his base was an evil roller rink. It's impossible to take seriously.
Nightmare Retardant: Whereas Tarantulas's general characterisation is pretty much Nightmare Fuel, his reactions to when things don't quite go his way are significantly less dark. His Oh Crap moments are some of the funniest in the series.
One True Pairing: Dinobot and Rattrap are a very popular pairing, also Dinobot with Primal in that Defrosting the Ice Queen way. Dinobot's small smile at the end of Gorilla Warfare probably started it.
Rescued from the Scrappy Heap: In quite possibly the quickest instance of this trope, Waspinator. At the very start of the show everyone hated him, including the writers, due to his annoying voice and personality. The writers responded by making him the Butt Monkey which, alongside with his Vocal Evolution that made his voice endearing rather than obnoxious, caused him to explode into the show's most popular character.
Rewatch Bonus: Word of God revealed that Dinobot knew he was going to die five episodes before he actually did right up til the last moment. Rewatching said episodes with this knowledge causes a lot of Dinobot's actions and dialogue to take on a whole new meaning.
Saved by the Fans: Waspinator was set to die at the start of the second season along with Scorponok, but the creators were aware of how popular he was with the online fanbase, and that Terrorsaur was becoming fairly redundant with the much more successful traitor of Tarantulas on board.
Seinfeld Is Unfunny: Not the writing or the show itself, but the animation. Back when the show first came out, the cgi was absolutely stunning for a television show let alone a show for kids. While the animation did improve noticeably over the course of the series, the show's animation still looks like something off of a Sega Dreamcast game compared to later fully cgi shows.
Special Effects Failure: The early episodes (obviously, due to technology limitations) look like crap, there's also several other moments which combine this with Off Model (such as Rattrap reverting to his old CG model in Code of Hero). Plus there's seams on several of organic beast modes if you look closely.
The explosion in Other Voices, Part 2 consists of real elements poorly composited over the animation. Similar techniques are used in many instances when Inferno uses his flamethrower.
And the fun doesn't stop there when you get down to analyzing individual episodes. Bad Spark comes off like a horror movie, between the fetid-swamp setting and the mass-murderous psychotic Predacon lurking for blood (oil) throughout. And, sweet Primus, that ending scene. And then there's the burned-out wastelands that make up the bulk of the second season's scenery, with the clear and present knowledge that most of the natural life on the planet is dead or crippled after the Eldritch planetbuster at the end of the last season. A lot of the fighting is surprisingly brutal in some episodes. And on, and on...