Awesome Music: Just try to hum that theme song without getting it stuck in your head.
The entire score of "The Wrong Trousers" is a huge step up from the synthesized music from "Grand Day Out". It has a great horror feel to it, with the exception of the Train Chase sequence, which is set to comical ragtime.
The series is quite popular with the French, who enjoy the quirky British humour.
It's also quite a hit in Japan, even having a advertisement with them in it.
And, of course, in the United States, leading to their (brief) partnership with DreamWorks Animation. As a matter of fact, after Harry Potter and Doctor Who, Wallace and Gromit are probably the third-most likely example of many American kids' first exposure to British pop culture.
Magnificent Bastard: "The Wrong Trousers": Feathers McGraw is a penguin who imitates a chicken while committing robberies. Taking advantage of Wallaces hospitality, Feathers drives Gromit out of the house by making him think he's being replaced and then traps Wallace in the reprogrammed electronic trousers that Wallace gave Gromit as a birthday present and runs him wild through the town. Feathers then uses Wallace to steal a diamond from the museum and when confronted by Gromit with a rolling pin, pulls a gun on Gromit. Feathers then narrowly escapes during a harrowing pursuit on a train set while nearly outsmarting Gromit at every turn.
Feathers crossed it when he pulled a revolver on Gromit and attempted to fire it at him and Wallace while trying to escape with the diamond he stole. He gets worse in his return in Project Zoo, in which he enslaves zoo animals into powering his diamond-making machine by imprisoning their babies in cages and placing them in dangerous environments such as over pits of spikes or lava pools.
Lord Victor Quartermaine is willing to kill the Were-Rabbit (even though he knows it's really Wallace, and even more so than ever BECAUSE of it) just so he can marry Tottington for her fortune.
No Such Thing as Bad Publicity: As mentioned on the trivia page, news stories of Nick Park accidentally leaving props from A Close Shave in the back of a New York taxi in 1996 are the main reason anyone in America heard of the series, let alone made it popular, in the first place.
Sacred Cow: Given they were a lot of people's introductions to Stop Motion and such formed a huge part of many fans childhoods, criticizing the shorts online is not a good idea.
The Wrong Trousers has the model train chase, especially the part where Gromit lays out the track from the front of the moving train.
Gromit turning his sidecar into a plane in A Close Shave.
That One Sidequest: Trying to get all the coins in the Gamecube version of Project Zoo? If you are, then the first Lava World bonus stage will have you curling up in the fetal position and whimpering. Gromit has to climb a series of platforms while avoiding rolling barrelsthrown by a gorilla. The problem? The game contains a glitch where most of the barrels are invisible to the player. Barrels that result in instant death if touched. Oh, and did we mention you're on a time limit? Getting the coins from this level requires truly psychic guesswork and timing and the reward? Short clips from "The Wrong Trousers" and a single preview from the 'Cracking Contraptions' series.
"The Wrong Trousers" is a mild example, still near-universally considered the best in the series, but with the others all following close behind. A much bigger example is the short's villain, Feathers McGraw, who's considered such an iconic character that none of the succeeding villains are anywhere near as well-remembered.
Nick Park himself stated he was unwilling to make further projects for the mere sake of continuing the series, wanting each one to at least try matching up the previous and testing new boundaries. He also stated his unwillingness to make new projects without the now deceased Peter Sallis, feeling fans wouldn't accept a soundalike.
The famous "track laying" scene in "The Wrong Trousers" is one long display of the most mundane practical effect ever: pushing the puppet slightly as the camera takes an exposure to create a believable and, more importantly, real motion blur effect. And it looks amazing!
From the same short, the rather mundane but extremely well-done special effects of Gromit pouring a cup of tea, and jam splattering onto a piece of toast in mid-air. All done completely with stop-motion, and no computers!
Even more mundane: Gromit's knitting is all real, done with toothpicks.
You're sure to feel sad for poor Gromit when he feels so pushed out by the manipulative Feathers that he has no choice but to run away from home.
Wendolene in "A Close Shave", having been forced take part in Preston's sheep rustling and is wracked with guilt when he frames Gromit for the crime. Then her canine companion turns on her too, nearly feeding her to the same machine as the rest of the sheep. It's only after the efforts of Shaun and Gromit that she's free from her terror.
Fluffles in "A Matter of Loaf and Death", being owned by an abusive master not afraid to physically hit her if she steps out of line and being forced into an accomplice for murder. Luckily, things do get better for her thanks to her budding relationship with Gromit.