Buffy the Vampire Slayer

Buffy: A world of no.
Spike offers Buffy a drink and she says 'a world of no,' a line similar to the lyric 'a world full of no' from one of Roxie Hart's songs from OMWF's fellow musical, Chicago.

Buffy: Going Through The Motions
At the very end of Buffy's first song "Going Through the Motions" she walks up steps to a landing in the graveyard overlooking the cemetery. As she finishes singing her last line "I just want to be alive!" she stakes a vampire whose dust explodes around her. This is based on the scene in "The Little Mermaid" when Ariel is on top of the boulder in the ocean overlooking the beach. As she is singing her last line "Part of that world" a large wave crashes behind her.

Buffy/Giles: Training montage from an eighties movie / inspirational power chords.
Buffy is referring to the decided trend in 80's movies to include a "training montage" (nor just Rocky and the Karate Kid--many 80's movies have that, such as the ones about dancers). Power chords are a type of simplified chord played in a lot of rock music - the types of songs that usually accompany 80's movie training montages.

Sweet: That's entertainment... Sweet is referring to a 1953 song of the same title. The song was first played in the film The Band Wagon, and quickly became a huge hit. The song remained popular ever since, and is now often used in shows and films which deal with show business (particularly sentimental views of past glories from stage and screen).

Xander: Respect the Cruller and tame the Donut! This line is an homage to the film Magnolia in which Tom Cruise's character, Frank T.J. Mackey, is a male inspirational speaker. One of Mackey's common themes is that men should be more dominant over women. Xander is reciting one of Mackey's catch-phrase lines, but using "cruller" and "donut" as euphemisms for parts of the male and female anatomy.

Visual: Lethe's Bramble
The flower that Willow uses to alter Tara's memory is named after one of the rivers in the underworld of Greek mythology. The river's waters allowed the dead to forget their lives on Earth.

Xander: Respect the Cruller! A cruller is a type of donut, but the dough is braided into a long oval shape rather than baked in a traditional circle. Since the dough is not raised, they are usually more airy and less dense than a regular donut. French Crullers are a variety which have a circular shape, but scalloped edges.

Buffy: So, Dawn's in trouble. Must be Tuesday.
Buffy is referring to the fact that Buffy has been airing on Tuesdays since January 27, 1998. Plus, Dawn pretty much gets in trouble for most of the episodes since she's appeared.

Spike: Saw a 600 pound Chirago demon makin' like Yma Sumac - that one'll stay with you.
Yma Sumac is a Peruvian singer with a very impressive vocal range.

Sweet: I can bring whole cities to ruin and still have time to get a soft shoe in.
Soft Shoe was a popular Jazz step and is still commonly used in some Jazz routines.

Buffy: I feel like I should bow or have honor.
Since she just kicked a board in half she is referring to Martial Arts testing where students must pass a test and bow.

Anya: When I get so old and wrinkly, that I look like David Brinkley.
David Brinkley is a published, award-winning journalist who happens to be quite old and wrinkly.

Spike: ...there'll probably be a parade. 76 bloody trombones.
Meredith Willson wrote the song "76 trombones" for the musical The Music Man, which was a hit both on Broadway and as a 1962 musical motion picture.

Sweet: I bought Nero his very first fiddle.
According to legend, Emperor Nero Claudius Caesar just watched and played a fiddle while Rome was burning.

Buffy: Whistle while you work so hard all day to be like other girls.
Disney's cartoon movie Snow White and the Seven Dwarfs featured a song called "Whistle While you Work"

Spike: Some day he'll be a real boy.
An allusion to Pinnochio, a story about a puppet who comes to life. He can move and talk but is still made of wood, and he longs to become a real boy.

Spike: You should go back inside. Finish the big group sing. Get your kumbayayas out.
A dual reference to the famous camp song Kumbaya, and to the 1969 Rolling Stones live album Get Yer Ya Yas Out.

Tara: This demon, that can be summoned, some sort of Lord of the Dance... Oh, but not the scary one. Just a demon. Lord of the Dance is a Celtic themed dance production, headed by Michael Flatley of Riverdance fame. It is a common target of jokes because of a perceived arrogance in the title and the fact that neither the stage production nor the video recordings sold well at all compared to Riverdance.