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.
Complaining about People Not Liking the Show: Mentioning that you think any of the animated movies improved on the works, or that you simply dislike reading them because of Tolkien's writing style, expect to be called "Illiterate". Even if you are a Hardcore Book Worm.
Creator's Pet: Tom Bombadil, the fact that he was based on Tolkien's childhood doll doesn't make it any better.
Die for Our Ship: Poor, poor Arwen. Aragorn/Boromir, Aragorn/Legolas and Éowyn/Aragorn fanbrats hate and bash her like there's no tomorrow.
This goes back much further than the movies, too. The fact that she was a late addition (Tolkien didn't create her until the third draft) really doesn't help her any, nor does the fact that she doesn't actually do anything, and her love story with Aragorn is in the appendices. The movies gave her Glorfindel's part because they wanted her to do something other than hang out in Rivendell and look pretty—given that all her characterization is developed in the appendix, they had to toss her something. Fortunately they did not go with their original idea, which was to send her to the freaking battle of Helm's Deep like some kind of Xena the Elven Warrior Princess. Even Liv Tyler despised that idea.
Ending Fatigue: Some consider the end to be too long. Tolkien wasn't eager to pawn off a pat "happy-ever-after" ending. Instead, the heroes' homecoming is just as important a part of the journey as it was in the old epics it emulates.
Arwen as well, mostly thanks to the film — which slightly expands on her role, combining it with the most Badass elements of Glorfindel, and bringing in most elements of the love story which Tolkien left to the appendices.
Peter Jackson jokingly suggested that they wanted Imrahil to appear on film, but only if they could get Schwarzenegger to play the role. Figwit is probably the epitome of this trope, but was not in the book.
And no mention of Tom Bombadil? He's practically the series Chuck Norris. Of course, he's also The Scrappy to some.
"At that moment there was a knock on the door, and Sam came in. He ran to Frodo and took his left hand, awkwardly and shyly. He stroked it gently and then he blushed and turned hastily away."
Iron Woobie: Frodo is the definitive example of this trope.
It Gets Better: They spent a whole book getting to Rivendell. Millions of readers were happy to wait.
It Was His Sled: Gandalf comes back. The Ring is destroyed. Aragorn gets crowned King of Gondor.
Jerkass Woobie: Gollum, in a Jekyll/Hyde split personality example: the Smeagol persona is a sniveling Woobie, while Gollum (his desire for the ring given form) is pure Ax CrazyJerkass.
Less of a Jerkass or a Woobie than Gollum, but still qualifying, is Boromir.
Magnificent Bastard: Sauron. Especially after reading the appendixes and learning about everything he did to set up his victory—not to mention his role in The Downfall of Númenor.
and "Gandalf for President", both popular rallying cries from The Sixties.
"Tolkien is Hobbit-forming". Also, anything having to do with Hobbits.
Political discourse: "Frodo failed, X has the ring" or "Y is like the One Ring, everyone wants it"... Strangely influential, perhaps because many poli-sci geeks see the Ring as an allegory for nuclear weapons or the corruption of tyranny.
"Another piece of Mordor", often seen scrawled on ugly building projects under construction.
Even the One Ring itself gets this. Way too many people have used replicas of this symbol of evil as wedding rings.
Newer Than They Think: Orcs and Balrogs at least — you'll find them in many generic fantasy settings alongside mythological creatures, but LOTR is the first (published) work to use them. "Orc" is a Quenya Elvish word (Sindarin has the variant "Orch" which gives the wonderfully apropos plural "Yrch"), while Balrog is Sindarin for "powerful demon".
Nightmare Fuel: Some of the scenes involving the Nazgul were pants-shittingly terrifying, as well as the general feeling of panic and being hunted while the hobbits are escaping the Shire. Also, Sauron.
Older Than They Think: The idea of a ring that makes you invisible goes back to the Ring of Gyges from Plato's Republic. Considering how well read Tolkien was, it's probably where he got the idea in the first place.
Ron the Death Eater: Poor, poor Arwen. Boromir, Denethor, and Thranduil definitely tend to get this treatment too in fan fiction.
Seinfeld Is Unfunny: Almost every modern fantasy copies from it to some extent or another; so much of the genre is aimed at children that by the time a reader gets to the Real Thing, they've seen it before...
Values Dissonance: Allusions to Aragorn's inherently kingly status and confidence (almost magical, as mythology was wont to do) are greatly reduced in the movie, to the point his major character arc is reversed to personal reluctance to be king.
Vindicated by History: The book wasn't really popular until the Vietnam war and then the reading public started seeing parallels between Vietnam and the War of the Ring.
What Do You Mean, It's Not Political?: There are many, MANY interpretations of LOTR as a thinly veiled allegory of World War II. In particular, according to this view, Sauron is A Nazi by Any Other Name, and the whole Scouring of the Shire episode is a satire on Communism. Tolkien started to shoot down these interpretations when he was still alive, but when has Word Of God ever stopped fans (or not-fans)?
"I cordially dislike allegory in all its manifestations, and always have done since I grew old and wary enough to detect its presence." -Tolkien, responding to this in a forward to a later edition.
Tolkien's old buddy CS Lewis adored allegory, hence his Narnia books being nothing but allegory. Such a falling out over allegory in Narnia (and other things Lewis did that pissed Tolkien off) that Tolkien and Lewis didn't speak for awhile. They agreed to disagree and got over it, buddies again, but it must have really rankled Tolkien to the end of his days when people saw allegory in LOTR.
The Woobie: Faramir. For one, his father says straight out that he would have preferred that Faramir die. Then he essentially tells Faramir to go try and die anyway.
They Just Didn't Care: Despite the rich languages that Tolkien invented, and the number of people fluent in them even back in 1978, composer Leonard Rosenman used made-up gibberish for the soundtrack's choral chants, with the occasional word like "Sauron" or "Mordor" thrown in.
Rankin-Bass Animated Film
Anvilicious: In case you miss the deeper meaning in any particular part of the movie, there's usually a song to explain it to you. Or two. Or three. See the page quote for a good example.
Can't Un Hear It: Sean Astin's distinctive accent for Samwise Gamgee is very similar to one of the most famous (extant) audio narrations of the book, though Astin claims he wasn't aware of the audio version. Eerily, Sam is never actually written with such an accent in the books, making it all the weirder.
Crazy Awesome: Viggo Mortensen. During the filming of Helm's Deep, he caught a sword in the face, and broke a tooth. His solution? Superglue the tooth back together and keep filming. All of the other actors were afraid he was going to end up killing himself before they finished filming, due to his insistence on performing lots of extremely dangerous stunts himself. Even the stuntmen were impressed by his dedication, and ability to ignore pain and injuries while filming. See Throw It In and Fatal Method Acting for more examples.
Creator's Pet: Aragorn comes across as this to some people.
Crowning Music of Awesome: Howard Shore's score is usually recognized as one of the best in film history, sometimes even by people who weren't fans of the movies. The three Academy Awards (two for best score and one for best song) didn't hurt this either.
Lux Aeterna's song, Requiem for a Tower, which was present in the trailer of The Two Towers. It's used for many youtube videos.
Ending Fatigue: Common complaint of the end of the third movie. The book has six chapters after Mount Doom, featuring crownings, burials, info on the War in the rest of Middle-earth, the journey home, the Scouring of the Shire, and the hobbits work to restore it and settle down again, which fails for Frodo, who leaves in the end.
It also doesn't help that the screen fades out in about 5 places and really looks as though the film is ending there, only for it to reappear again. Slightly different cinematography may have made this a much less common complaint.
Discussed on the cast commentary track, where somebody (one of the Hobbits I believe) says that the fade after "Here, at the end of all things" could be the end of the movie, albeit a very artsy and far-out ending.
Genius Bonus: A little bit of extra awesome for those versed in The Silmarillion. In the scene in the extended edition where Sam tells Frodo, "There's light and beauty up there that no shadow can touch," the star he sees is no ordinary star. That's the Star of Earendil, the Evenstar — yeah, the one Arwen was named after. We would call it Venus. In Middle Earth, though, it's an elf on a flying ship with one of the three Silmarils, which contain the light of the Two Trees; holy light that predates the sun and moon. The Star of Earendil was the source of the light contained in Galadriel's Phial.
Genre Turning Point: Along with the Harry Potter series, the LOTR trilogy proved that fantasy films didn't have to belong to cheesy B-movie fare and could be critically and commercially successful. A literal torrent of high-budget, CGI-heavy fantasy, sci-fi and superhero blockbusters followed in the next few years, and there seems to be no end to it.
Ho Yay: Frodo and Sam, as usual. Actor Ian McKellen, who is gay, was interested in the close relationship between the two characters. He noted the attention to detail in the pair's close relationship from page to screen, such as when Sam grabs Frodo's hand after he awakens from unconsciousness. In fact, both pairs of hobbits can reasonably be called Heterosexual Life Partners. It's worth noting that Sam is ironically the only hobbit to show interest in any specific woman in the films. In this regard, Merry and Pippin might be closer to this trope than Frodo and Sam.
This is pushed Up to Eleven in the DVD cast commentaries for the three films (but especially The Two Towers), where all four actors play with this trope at one point or another.
Aragorn/Legolas also get some of this. Actually, Aragorn/anyone do. Viggo kind of encourages it.
“Instead of a Dark Lord, you would have a queen, not dark but beautiful and terrible as the dawn! Tempestuous as the sea, and stronger than the foundations of the earth! All shall love me and despair!”
Narm: Galadriel's rant when she is tempted by the ring. For some nightmare fuel of the high octane variety. For others it can be cringeworthy.
Thank you, now that song is stuck in my head again.
Just about every bonding scene between the hobbits, Frodo and Sam, rely on the film earning audience respect for them beforehand.
Gollum again.
Boromir's anguished rant at no one in particular in Fellowship Of The Ring, punctuated by falling into a pile of leaves. In any other film, utterly ridiculous. But Boromir's Tragic Hero status and Sean Bean's acting sell the hell out of it, and it's a near-Tear Jerker.
I always got the notion that it was Frodo who pushed Boromir onto the pile of leaves, as he was badmouthing Frodo and his race at the time.
The music did not help. It might as well have been the best musical theme to depict pure evil ever written.
It, along with the Witch-King's cries and the look of the city was meant to invoke the feeling of a visit to dentist, I kid you not.
Nightmare Fuel: Smeagol turning into Gollum at the beginning of Return Of The King.
Shelob. If you are an arachnophobe at all, you will have nightmares for a good while.
The Woobie: Frodo. Perhaps overly so, as a common criticism of the character (or at least Elijah Wood's portrayal thereof) is how he spends basically the entire trilogy with a pained expression on his face.