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.
YMMV: Superman
Film
Anvilicious: Superman IV: nuclear weapons are bad! Did you get it?
Foe Yay: Ever since that wonderful mouth to mouth scene in Smallville.
Genre Turning Point: While not the first superhero film, the original Superman opened a whole new era for this genre (which either carries on to this day or ended with a similarly influential The Dark Knight Saga).
Hell Is That Noise: Kryptonite made a pulsating noise when Supes opened the lead box. The original Dolby Surround mix (available in later pressings of the Theatrical Cut on DVD, as well as VHS and laserdisc) is louder.
The 5.1 mix uses all channels during the Sonic Warning scene (This is Lex Luthor. Only one thing alive of less than four legs can hear this frequency...)
It was spoken-word because the filmmakers discovered too late that Margot Kidder couldn't sing. Perhaps dubbing in a professional singer's voice would have put them over budget or something.
The depowering scene in the theatrical cut of Superman II.
The last scene of the Executioner in the TV version of Superman The Movie.
The faint, echoing screams of the Phantom Zone villains inside that spinning crystal.
Replacement Scrappy: In Superman Returns: Kitty's just no Teschmacher for many viewers. Earlier, in Superman III the character of Ross Webster was lambasted for being a cheap Lex Luthor knockoff.
Seinfeld Is Unfunny: Although the first movie basically invented the modern superhero film, looks impressive even after 30 years, it is often dismissed as a museum piece with little appeal to modern audiences.
All those things I can do. All those powers. And I couldn't even save him.
Visual Effects of Awesome: Many. One of the most striking visuals even today is the scene in the first film where Superman rebuilds the San Andreas Fault. Superman Returns has the whole sequence with the 777 jetliner rescue.
Villain Decay: Really, compare the Lex Luthor of the comic books to the sniveling, real estate-obsessed loser from the films. It's no contest.
What an Idiot: After Superman first makes his presence known in Metropolis by stopping many crimes in a single night, Lois deliberately asks about and prints for all to read one of his non-Kryptonite Factor weaknesses —his inability to see through lead.
What The Hell, Casting Agency?: Aside from any considerations of talent Kate Bosworth was an odd choice to play Lois Lane in Superman Returns on age alone - Bosworth was 23 (and looked it), playing a character roughly a decade older. This is especially irritating when one considers that Parker Posey's in the cast and would have been perfect for an older iteration of Lois.
The Woobie: Clark Kent by the Daily Planet elevators, a lovable nerd who has just been brushed off by Lois, ignored by everyone else and treated rudely by a person inside one of the cars and now all alone as he waits for a downward car. Don't feel too sorry for him though, for outside, Lois' helicopter is going to crash and his Crowning Moment of Awesome is about to begin.
Comics
Alas, Poor Scrappy: Supeboy-Prime's apparent demise in Blackest Night. Of course, it might not have happened. The Legion Threeboot featured a very creative storyteller who looked just like Superboy in one issue, and we now know the Threeboot took place on Earth-Prime.
Pre-Crisis Superman was very much the dominant personality, with Clark Kent as mask he puts on in order to "hide." He noticeably wasn't very committed to it, as the Clark Kenting trope is quick to point out, and several times tried to just give up on the persona and be Superman 24/7
The idea that Superman was the dominant personality was theorized by Jules Feiffer, whose words were paraphrased by Bill the Snakecharmer in Kill Bill Vol. 2.
While that was the case in The Silver Age of Comic Books, several Bronze Age stories, most notably the "Mr. Xavier Saga" (no relation), came to the conclusion that he valued both identities equally, and felt miserable and stressed whenever he was forced to neglect either for an extended period of time. Without Clark, he had no way to ever relax; and without Superman, he couldn't help people in danger. *
"I tried to decide whether Clark or Superman is more important... and realized that to do away with one would be to kill half of myself—whoever I really am! So... I'd decided meek, mild-mannered Clark Kent will still walk the streets of the city—while up in the sky... the world will still watch and thrill to the sight of—a job for Superman!"
.
One good story involved a pair of gambling aliens separating Clark and Superman. All that happened was that there was two Supermans, and that when one of them was Clark the other felt compelled to be Superman, and vice versa.
Post-Crisis is the opposite, Clark is the dominant personality with no knowledge or memories of Krypton until well into his adult years and after he started operating as a super hero. This means that Clark comes off as a far more assertive and aggressive person than the Pre-Crisis "wimp." This makes Superman come off as stiff and artificial because, as Clark puts it, "Clark is who I am, Superman is what I can do."
Modern writers now suggest that there are actually three personalities, the first is Clark at home, who is a decent, normal guy like any other. Then there is Clark at the Daily Planet, still a nice guy if occasionally clumsy and a little goofy, likes to play things safe but also an ace reporter and Deadpan Snarker par excellence. Finally there is Superman, who is every inch The Cape and honestly believes in Truth and Justice, almost to a fault. He sees Krypton as his birthright, but not his home and tries to bring the best of that society to Earth while trying to steer away from its shortcomings.
Complaining about Shows You Don't Watch: Most haters of Superman argue that he is too powerful and boring, what they fail to realize is that Superman fights enemies that are just as powerful if not stronger, making the stories larger than life and is exactly what makes him so appealing.
Brainiac has been one since his introduction in 1958. When the Silver Age version is so evil that Superman has to resort to deadly force, you know he qualifies, and it seems like each new version has tried to up the ante.
Unlike most examples of this trope, most incarnations of Brainac don't have emotions, meaning they aren't sadistic. They still count as the above though...
Bruno Mannheinn
Neutron
Though Ursa and Zod are Abusive Parents on their own right, at least Zod is a Noble Demon. She's just a sadist about it.
Crazy Awesome: That time Bizarro managed to assemble an army of Supergirls from across the multiverse.
Vartox
Crowning Moment of Awesome: Superman's Shut Up, Hannibal! to Manchester Black: "Dreams save us. Dreams lift us up and transform us. And on my soul, I swear... until my dream of a world where dignity, honor and justice becomes the reality we all share - I'll never stop fighting. Ever."
Meta-example - The Superman radio showfought the resurrection of the Ku Klux Klan. And defeated the real one's attempted post-War revival.
And Pink Kryptonite. Lookin' pretty hot there, Jimmy.
Crowning Moment of Heartwarming: Considering Superman's idealistic nature, he's prone to causing a whole lot... but let's face it, one of the biggest one has got to be the Kents' discovery and adoption of the infant Kal-El, regardless of the version of it.
Fridge Logic: How the hell is Superman vulnerable to his own planet?
We are also vulnerable to portions of our own planet that are radioactive.
Kryptonite has been subject to so much Fridge Logic over the years (like how you can just about buy it on any street corner on earth by now, etc..) that it's best to mutter Bellisario's Maxim and move on...
Symbolism-He's an immigrant to America, kryptonite is the old country.
Hilarious in Hindsight: In a letter at Superman: Man of Tomorrow #3 a couple of readers said that it would be cool, if Lex Luthor killed Superman and took over his titles, like Action Comics. What do you know, fifteen years later the second part of their wish came true. And it was awesome.
Ho Yay: His comments about how Jimmy looked in a bow-tie were not subtle. This is arguably a variation on Kissing Under the Influence since he had just been exposed to pink Kryptonite.
Kryptonite, as a object/substance/etc. that the forms the fatal weakness of someone. Similar to an Achilles' heel, but that's more Attack Its Weak Point.
Superheroes wearing their underwear on the outside.
The terms "superpowers" and "superhero". Before Superman, they were "mystery men" who had "extra-normal abilities" or similar terms. Superman introduced the all-purpose "super" prefix.
"It's a bird! It's a plane!" And it's variation "Is it a bird? Is it a plane?".
Motive Decay: After his brain damage was cured by the demon Neron in Underworld Unleashed, Atomic Skull has mainly appeared as just a superpowered thug-for-hire without any real motives.
After getting her book, Silver Banshee now goes around causing trouble for no reason, and her tribe seems to have been forgotten. She can now be motivated by money, as well.
Originally, Prime wanted to replace New Earth with a "perfect" Earth—Earth-Prime. When he found out this was impossible, he just wanted to destroy everything.
Justified, 'cause when Prime tried his hand at bringing the end of the world, he wasn't exactly thinking straight. Later his goals changed depending on the cicrumstances he found himself in.
Moral Event Horizon: In every one of his appearances, Superboy-Prime ends up finding new and horrific ways to become more and more of a Complete Monster.
If you exclude Countdown, there are two moments that definitely stand out as this MEHs. The first would be the Titan massacre (which started with My God, What Have I Done? and went on with a Freak Out), and the second was the heavily implied murder of his former girlfriend, Laurie. His status of Complete Monster hasn't been soldified yet, however.
In universe example, Mr. Mxyzptlk, also The Unpronounceable. Even the other characters think he's an annoying little snit. In reality, he's one of Supes's most famous enemies.
Stoic Woobie: When Lois at one point breaks off their engagement and returns his ring (with fair cause; marrying Supes is a daunting prospect for a dozen reasons), a brokenhearted Superman flies out to the middle of the Atlantic to try to calm down. There he bumps into Lori Lemaris of Atlantis, his ex-girlfriend, and confides in her how frustrating it is that he's the only man in the world who can never allow himself to get angry. He chucks the ring miles over the horizon. Then Lori asks, "Wasn't that Ma Kent's engagement ring?" Supes realizes she's right and bolts off over the horizon to retrieve it.
Strawman Has a Point: Superman in the Action Comics comic Muscles For Money. Sure he was being a jerk, but his argument that he deserves a reward for all his good deeds does have merit.
Tear Jerker: The Death and Return of Superman arc. Especially having to do with his parents is almost hard to read.