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: The Green Hornet
General
Adaptation Displacement: For baby boomers, the 60s television adaptation pretty much completely displaced the original radio series and movie serials in their consciousness. Later generations are familiar with the property primarily through the NOW Comics and Dynamite Entertainment comics series, and have little (if any) familiarity with either the radio series/movie serials or the TV series.
This got bad enough that The Film of the Series has a comic-book motif in the end credits.
Ensemble Darkhorse: Thrown all across the board with Kato throughout the franchise. He began as a simple sidekick but over the years, he grew into popularity. Most modern versions have Kato as the muscle while Green Hornet was the central figure. In the movie, everything is taken to the next level. Kato was basically responsible for everything that the team did, from the gadgets to being the muscle. While Britt is still the main character and the one calling the shots. The movie does involve them clashing with each other over who was in charge. Most people agreed that Kato was the best part of the movie, so it's likely they intended the movie to be like this.
Comic Series
Shipping: Britt Reid and Casey Case. Hinted at in the radio series (in at least one episode Sentinel reporter Ed Lowery banters with Miss Case about her harboring a crush on Reid). Subtly made part of the subtext in the television adaptation in at least two episodes ("The Frog is a Deadly Weapon" and "Invasion from Outer Space"), in spite of firm insistence by creator George W. Trendle that the relationship between Case and Reid be kept strictly professional. Made "canon" in NOW Comics's "Hornetverse", where Britt Reid II marries Casey Case after his retirement (Trendle having died in 1972, the subsequent rightsholders apparently discarded any objections to a Reid-Case romantic relationship).
Film
Crazy Awesome: Britt's description of Kato basically boils down to this.
"You're like a human Swiss Army Knife!... it's a thing that you keep pulling things out of, every time you think you're done pulling out things, another cool thing pops right out and that's you!"
Hilarious in Hindsight: In a twisted form of Product Placement, Crystal Clear (played by James Franco) names the designer labels his henchmen are wearing; one episode of MTV's Spider Man series, based off the movies James Franco is involved in, starts with Peter Parker referring to a shady guy and his henchman as "Dolce and Gabbana".
A lot of Jay Chou's Concept Videos could possibly act as Kato's entire backstory.
Ho Yay: Good God. Some people bring their Slash Goggles to movies. Some movies forcibly glue them to the viewers' faces.
"I'm surprised you haven't hit on me yet!"
"Shen Di Forever!"
(Psst: it's "Xiong Di" in pinyin. And it actually does mean "brothers", so, umm, let's not go there please.)
Brit: "I want you to take my hand and come with me on this adventure!" Kato: "I'll go with you, but I don't want to touch you."
Kato changed Brit's diaper while he was in a coma. (Granted, the coma was his fault...)
Leonore: "Maybe you two kiss, but I'll have nothing to do with you!"
Awesome Music: Ladies and gentlemen, Al Hirt. The piece is not only enormous fun to listen to, but is so fast-paced that the King of Trumpet himself allegedly passed out when the recording was done.
Draco in Leather Pants: Double Subverted in the second broadcast episode of the TV series ("Give 'Em Enough Rope"), a female lawyer friend of Britt Reid's is captured by the Villain of the Week, and is rescued by the Hornet, in the next scene she's telling the story to Britt and gushing about the Hornet, wonders if he's really as bad as everyone thinks, and says she hopes he never gets caught, and if he does, she'll defend him for free. Subverted in that the Green Hornet really is a misunderstood, amligned hero. Double Subverted since she doesn't know that.