In the Angel episode ‘Guise Will Be Guise‘, Lorne asks Angel if he’s happy. Angel answers ‘yes’, to which Lorne replies, ‘Now once more, with less feeling?’.

In the episode Inca Mummy Girl, we see Oz (in his first appearance) wearing a New York Islanders (a hockey team) t-shirt.

At the end of the episode Potential, Dawn is studying a book whilst talking to Xander. The book has a picture in the middle of the page - the scene then cuts to Xander, and quickly back to Dawn again, and the picture is missing, without her turning the page.

Here’s something I’ve never understood: How did Angel go from being his relatively normal,brooding self living in an L.A hotel in the 1950’s, buying blood from the butcher, to being a straggly-haired, smelly hobo, living on “a rat a month”, as Whistler says?

The Halloween 2005 episode of the TV show Smallville entitled ‘Thirst’ references Buffy the Vampire Slayer several times. In the episode, a form of rabies spreads in a number of sorority girls that its side-effects resemble the characteristics of being a vampire. The episode revolvs around a sorority girl …

In The Wish, at 22:13. In Prophecy Girl, the Master tells Buffy that “prophecies are tricky creatures. They don’t tell you everything. You’re the one that sets me free! If you hadn’t come, I couldn’t go.” So how is the Master released in the alternate reality in The Wish?

In The Witch, seen at 19:34.

Cordy puts on her seatbelt as soon as she gets in the car. When the teacher tells everyone to get out, she never undoes she seatbelt (and there isn’t time for her to do it offscreen), but next we see it’s undone.

In Bring on the Night, Dawn tells a suspicious Principal Wood that the reason she and Buffy are in the basement with a shovel is because they were burying a time capsule as a science project. Dawn says their capsule will contain the message: “Hello people of the future, kids …

In the episode Angel, Darla asks Angel if he thought Buffy would see his face, his true face, and would give it a kiss. In other words, she highly doubted that Buffy would ever be able to accept Angel to the extent that she could kiss his demonic vampire-face, the …

In the episode Same Time, Same Place, Willow asks for Anya’s help with a locator spell, and Anya asks if it will be sexy. This is a possible reference to the sexed-up Draconian Katra spell which Willow and Tara performed in Who Are You?

Alyson had a guest appearances in “That 70’s show” in the episode “Sally Simson”. Where she plays a police that Kelso make friends with and also attemptes to set her and Fez up for a date.
This ep aired February 18. 2004

How in the season two episode Passion did Angel beat Jenny Calendar up the stairs? it seemed that she had almost escaped because he had fallen over the mop but somehow he arrived in time to kill her.

Zombiepumpkins.com is a website offering Jack-O-Lantern ideas for Halloween inspired by movie, TV and music celebrities - including Spike and Buffy stencils.

In the second season episode Phases, Xander refers to Moon Pie, made in Chattanooga, Tennessee. From MoonPie.com:

“Early in the 1900s, while servicing his territory of Kentucky, Tennessee and West Virginia, Mr. Mitchell was visiting a company store that catered to the coal miners. He asked them what they might enjoy …

The character of Olivia appeared in three episodes in season four (The Freshman, Hush, and Restless), and was mentioned in one other (Who Are You?). These are the four episodes of that year that Joss Whedon wrote. She was was at least mentioned in every Joss Whedon episode …