Good grief, Fagin. FAGIN. How do we properly trope him? He's cast in this adaption in a much lighter and comedical tone. But the lovable rogue's character bounces all over the place. One minute he's fun and endearing, the next mentally unhinged, if anyone stumbles upon his secret horde. He gives the orphaned children of London a home, and teaches them how to survive, whereas the alternative is begging on the streets or ending up in the Workhouse. But despite the wealth he's accumulated, doesn't do much to improve theirs (or indeed his own) squalid living conditions.
Sikes can sometimes come under this too, particularly in his relationship with Nancy. It can be played as pretty much everything from him truly loving her and killing her more out of grief that she's betrayed him than outright anger, to being fairly disinterested in her and tolerating her presence for as long as she worships him.
Nancy's terrific "Reason You Suck" Speech to Bill after grudgingly helping steal Oliver back. He may have struck her to get her to kidnap the boy, but the moment she sees him about to beat Oliver, she puts herself between them. Even when Bill draws a belt to whip him, she grabs it and tells him that he will not lay a finger on the child. She doesn't care if he hits her again or kills her, she won't allow any harm to come to Oliver. She also reminds Fagin that she could ruin him, Sikes and the rest of the children with one word to the authorities - which she will do even if it means she goes down with them. The fact that Bill doesn't try to beat Oliver again says he knows she was not making an empty threat.
Nancy's death can also count as a Dying Moment of Awesome depending on how they choose to play it (certainly the case in the film). While Bill is beating her, she screams as loudly as possible to alert Mr Brownlow and at least ensure Oliver gets to safety.
The song "I Shall Scream". While it can be pretty funny, it has absolutely no bearing on the plot. Rather fittingly, it's left out of the 1968 movie version. It establishes a romance between Mr. Bumble and Ms. Corney, which is referenced later during one scene in the second act, and is thematically important: the Bumbles are evil, selfish people, and thus they make each other miserable rather than happy.
Cleverly subverted with "Oom Pah Pah". Upon first viewing, it's just a merry drinking song to get everyone in a good mood and doesn't appear to have any bearing on the plot. Then Sikes comes in and Nancy uses it as a diversion.
Due to the musical playing around with Fagin's character in ways that both make him more likable and also harder to figure out, he's one of the favourite characters.
Nancy too if you want to get technical. She doesn't appear for a good while but gets some of the best songs, and a memorably horrific death - so she's treated like the female lead when she's just a supporting character.
He's Just Hiding!: Nancy has been known to receive lots of cheers when her actress comes out to take the final bows - most of it from children who think it means she survived.
Love to Hate: The Bumbles are entertainingly horrid and get a fun song ("I Shall Scream") so they have a lot of fans, rather like the Thernardiers from Les Misérables.
Signature Song: Even people who haven't seen the show or the film know "Consider Yourself" instantly. Eddie Redmayne joked that any theatre kid in the UK knows the song and the dance off by heart (he played one of the pickpocket children in a Sam Mendes production at the age of ten).
Vanilla Protagonist: When he's surrounded by memorable characters like Fagin, Dodger, Nancy, the Bumbles and Sikes - Oliver doesn't have much to offer. They just have more entertaining songs and character arcs.
Twice he gets in big trouble because he just stands there like a deer in headlights - first when Dodger and Charlie pick Mr. Brownlow's pocket, then later when he accidentally knocks something over in a house he's trying to rob and he just stands there until the lights come on upstairs.
Arguably Fagin and Dodger suffer this as well when they allow Oliver to "go to work" when he's been with them less than 24 hours and is clearly still far too honest and naive to be ready to pick pockets. (This is mainly due to Adaptation Distillation since in the book, Fagin forbids him from going out for several weeks while he's being trained).
What Do You Mean, It's for Kids?: Considered a family-friendly show, despite it adapting many of the darker parts that came from the very grim novel (it does treat some of them with a more comedic age, making it more accessible for children). This includes the shockingly violent climax involving Sikes beating Nancy to death and then dying himself - by hanging in the 1968 or sometimes being shot. The 1968 film was even G-rated!
Author's Saving Throw: The stage version ends with Fagin's reprise of "Reviewing the Situation", with some implied Fridge Horror at Oliver's trauma at seeing Nancy and Bill's deaths. The film inserts a scene after the song where Oliver arrives back at the house with Mr Brownlow and hugs Mrs Bedwin, ending on a decidedly happier note.
Award Snub: As time has gone by, people are left wondering why Shani Wallis wasn't even nominated for Best Actress at the Oscars.
Ron Moodys impeccable performance was rightfully nominated, but he sadly didnt take home the trophy. He did win the Globe though.
Oliver Reeds chilling work went unnoticed.
Awesome Moments: "Oom-Pah-Pah" becomes even more awesome in the film version. On the stage, it's basically an Irrelevant Act Opener to set up Mood Whiplash when Bill Sikes makes his first appearance. Here, it's something Nancy spontaneously orchestrates to distract Bill and Fagin - allowing her to sneak Oliver out in the chaos. The song is the reason Oliver gets his happy ending.
During "Consider Yourself", Dodger and Oliver slide down a chute to where some fishmongers are preparing their stock. Dodger slides right into a poor woman who goes flying.
When Oliver, Dodger and Charley are running from the police - the latter two try to hide Oliver in the sack used for wrapping meat carcasses at a butcher's stall. Of course the butcher grabs the one Oliver is wrapped in and rips it off, foiling their ingenious plan.
As "Who Will Buy?" and its elaborate choreography comes to an end, we see Bill and Dodger hiding behind a tree with a look on their faces that says "WTF did we just see?"
As the crowd is stunned by Bill accidentally hanging himself, Dodger takes advantage of the situation by lifting one gentleman's wallet.
Fagin giving the children gin can be a little sad to watch with the knowledge of Jack Wild's alcohol problems as he grew older - resulting in throat surgery due to the damage.
"Oom Pah Pah" becomes that much more of a Tear Jerker due to its placement in the film - as when seeing it, you know it's going to lead to Nancy's horrible death.
Hilarious in Hindsight: Casting Oliver Reed as the drunken lout Bill Sikes was incredibly meta, given his legendary status as a member of the hard drinking foursome of British actors (along with Peter O'Toole, Richard Harris and Richard Burton).
Moe: Mark Lester is so adorably innocent as Oliver that he prompts this reaction.
Tough Act to Follow: It's very telling that a film version of a musical didn't win the Best Picture Oscar until 34 years later (Chicago if you're curious). This is also considered one of the last truly great movie musicals before Hello, Dolly! killed the genre at the end of the decade.
Unpopular Popular Character: Many lovers of the film feel Ron Moody's performance as the scoundrel Fagin, is the best adaptation of the character ever, and unmatched.
WTH, Casting Agency?: Oliver's singing is clearly dubbed by a female voice, and it can result in an odd Vocal Dissonance during songs like "Where Is Love?" - where the voice sounds much older (Kathe Green was twenty-four when she dubbed the singing). They originally had two other boys to dub Mark Lester, but discovered in post production that their voices didn't match his look - and Kathe was a quick replacement.