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.
Contested Sequel: The Meltdown is regarded as mediocre at best, with Dawn of the Dinosaurs being better received by the fanbase.
Although, also - Dawn of the Dinosaurs is quite contested, some consider it an absolute disaster, others call it the best of the trilogy.
Crack Pairing: Many, but notable ones include Sid and Ellie/Sillie and OT3s like Manny/Diego/Ellie. Supreme crack pairings include Peaches x anyone, but these have been mainly only discussed, though Sillie has been written once.
Creator's Pet: Both Scrat and Sid both show shades of this, Scrat since the first movie and Sid was Creator's Pet primarily in Ice Age: Dawn of the Dinosaurs. Because of this, the two have divided the base between fans, some disliking Scrat as being a nuisance (which he is) and Sid as The Scrappy as Flanderisation has ruined his character in between The Meltdown and Dawn of the Dinosaurs. ..... oh, and Scrat is voiced by Blue Sky Studios director/producer/founder Chris Wedge. Make of that what you will.
Draco in Leather Pants: Some fans like to over-romanticize Soto as this. One person to such an extent that the Sub-Zero Heroes become Ron The Death Eaters, Diego especially, because of the whole "brother with Soto" fanon.
Louis the molehog from the 4th movie. He just oozes Moe.
Also, the elephant seal Nick Frost played.
Crash and Eddie.
Everyone Is Jesus in Purgatory: "Roshan"'s name is Hindu for "Light At Dawn", and some fans have noticed that he does lead all the main characters out of their dark pasts and is a major impetus for them becoming True Companions.
Fanon: Manny's first mate and child's names being Millie and Wally, due to one author on fanfiction.net creating a ripple effect with the names.
A lot of fans like to think that Diego and Soto are brothers. But this interpretation turns sour when you realize that in the entirety of the Original, Soto is subtly making plans to kill Diego himself. Which his DILPing fans conveniently don't notice that leads to a Cain and Abel motif in the first movie if you subscribe to this fan theory, the Original film displays this trope terrifyingly, as every move Soto makes towards Diego is to devise the death of his own brother. Thus making it even MORE Darker and Edgier for the first installment.
Also, Soto being Not Quite Dead pops up somewhat commonly in fanfiction.
Roshan's name means "Light at Dawn" in Hindu and it could be argued that he leads the three main characters out of their dark pasts and is a major factor of them becoming True Companions.
If you pay attention, it seems that most of the movies contain a reference to the next movie in the series.
At the end of the original Ice Age Sid says something about global warming. Cue Ice Age: The Meltdown.
In Ice Age: The Meltdown, when Manny says mammoths can't go extinct because they're the biggest things on earth, someone counters “well what about the dinosaurs?” Cue Ice Age Dawn of the Dinosaurs.
Ellie takes a quick little jab at Manny in Dawn Of the Dinosaurs about not being able to relax about the baby, and wonders "how he'd deal with the teenage years". Cue the next movie, where she's a teenager and Manny is not dealing with it in the best way.
Some may wonder how it is that Peaches seems to pull so many more stunts then her mom Ellie. Obvious answer is that she’s younger and lighter, but the other reason is that Ellie was in a unique situation and had to figure out how to manage Possum stuff with a Mammoth body all on her own. Peaches had her mom to teach her how to do the basics, so she could come up with some tricks of her own.
Fridge Horror: In the first film, Manny was heading towards the freezing wasteland and it's implied that this wasn't too long after his family was killed. Was he trying to commit suicide?
In the cave painting scene, note that Manny's mate never stood a chance. Surrounded by speared humans, she could only shelter their calf helplessly. This makes perfect sense when you realize she had no tusks.
You realize that in the entirety of the first film, Soto is subtly making plans to kill Diego himself. Many have noticed this leads to a Cain and Abel motif in the first movie if you subscribe to this fan theory (and, please note, there is nothing to confirm that it isn't true), you suddenly realize that every move Soto makes towards Diego is to devise the death of his own brother.
If you pay attention then you’ll notice that there has been an on screen death in every movie so far. In the first it was Soto being crushed by icicles and Nadia drowning, in the second it was Fast Tony’s unfortunate glyptodont friend Stu (and later on, the killers themselves), in the third the bird thing that Sid threw off a cliff thinking it could fly, and Captain Gutt eaten by a siren and many of his minions falling to their deaths in the fourth.
The fourth film begins with Sid's family arriving in a log sled and tricking him into keeping care of his Grandmother before abandoning him again. Then the Continent begins to crack apart, and Sid's family is never seen again.
Buck and the dinosaurs were also beneath that continent.
Germans Love David Hasselhoff: The Ice Age films have all had decent box office runs in North America, but, at least in the case of the sequels, were overshadowed by the films from Pixar and Dreamworks Animation. Overseas, the series has been very successful, with the the third film and fourth film being the highest grossing animated films in the foreign market.
The movies, especially the first one, are really popular in Norway. One reason in particular being famous comedian with Bergen accent Dagfinn Lyngbø voicing Sid, who've more than once been recognized as making Sid several times funnier than the original.
Hilarious in Hindsight: In 2002, there were no known mammals extinct or extant that closely resembled Scrat. Come late 2011, one was described and named Cronopio. (However, it was not a squirrel, but part of a now-extinct mammal group, the dryolestoids. Furthermore, it lived in the Mesozoic Era, not the Cenozoic as most of the other animals in the films are.)
The presence of Buck in the third movie can be this once you discover that 20th Century Fox had once planned to adapt The Wainscott Weasel, a children's novel whose main character is also a weasel with an eyepatch.
Also in the fourth movie, we have Manny trying to break the sirens' trance by singing "The Candyman", which happened in the Dreamworks movie Madagascar. This would later head in the opposite direction, with the Running Gag of the rabbit on Gutt's crew being called the Easter Bunny... which would become a thing in Dreamworks' Rise Of The Guardians.
Ho Yay: We certainly get some moments with three male animals taking care of one baby. The two Held Gaze moments between Manny and Diego. When Diego meets Manny and Sid for the first time, he comments, "Oh, you couldn't have one of your own, so you decided to adopt". Also, in the third film when Diego and Manny are pressed up against each other, Diego says, "I feel all tingly!" Manny says, "Don't say that when you're pressed up against me!" "Not that kind of tingly!"
Diego taking the mortal blow for Manny during the battle with Soto at the end to protect him, as it is obvious that Soto's incisors slashed him fatally, and as he dies (the commentary for the first film confirms that he actually did die in that scene) he selflessly insists that Manny and Sid forget about him, since he wants to make sure Roshan gets home as much as they do now. This scene is especially heartbreaking if you remember that Manny has only recently lost his family, and now he is losing someone close to him all over again. His brimming eyes as he watches Diego leave them only serve to drive the point home.
This one may sound crazy, but the montage of the acorn "observing" Scrat and Scratte's moments together, accompanied by a rewritten version of Gilbert O'Sullivan's "Alone Again (Naturally). You can feel sorry for an acorn!
In the fourth movie when Manny with everyone returns to find the bridge where he told Ellie and Peaches to wait for him destroyed with no sign of either one of them; for a brief moment he closes his eyes, clearly thinking he's lost his family a second time.
Unintentionally Sympathetic: Soto tends to come off as this, as people feel sorry for him that he lost his pack/family, and was probably a pretty amiable guy once, and some people ignore his bitter desire for vengeance against the humans as it detracts from him being Unintentionally Sympathetic.
Viewer Gender Confusion: Roger, Buck's pterosaur mount, is referred to as female in the video game version of Ice Age 3.
What The Hell Casting Agency: Big, imposing Captain Gutt is voiced by Peter Dinklage... who's really short. Subverted in that he really is a great fit for the role, and his height has no affect on it. This could be because his voice is almost exactly identical to Geoffrey Rush.
Jeremy Renner was, at one point, set to voice Gutt, but he had to back out, and now it's kind of hard to imagine his voice coming out of something that looks like Gutt.