When discussing Penn’s murders, Cordelia and Wesley have the following exchange in Somnambulist:

Cordelia: “No lie. Gallagher’s changed his act more times than this dude has in the last two centuries. Why do you figure he’s still doing the same old schtick?”
Wesley: “Well, I mean it’s a classic, isn’t …

When Cordelia tries to persuade Angel to take a license plate to Kate in Somnabulist, the following line cut due to length:
“Just remind her that if it wasn’t for you she’d be the curdled gooey leftovers of a proto-Babylonian Burrower demon. Or words to that effect. You’ll pretty …

We discover in Somnabulist that vampires who are linked by blood (such as a sire) can sense each other’s presence and can be physically linked in dreams. This occured when Angel began to dream about the murders commited by the vampire he sired, Penn.

In Somnabulist, the following conversation occurs:

Angel: “Got held up in Romania.”
Penn: “Romania. What’s in Romania?”
Angel: “Gypsies.”

This is a reference to the Buffy episode Becoming (Part 1), in which we see gypsies give Angel his soul back.

Kungai demons, one of which is seen in Parting Gifts, are a powerful race of yellowy-green, Asian demons whose Tak horns suck the life force out of an enemy. They are relentless killers but die when their horn is removed.

When the mysterious demon hunter in Parting Gifts touches the demon blood at the side of the building, the hand belongs to a black person. We later find out that the demon hunter on the bike is actually Wesley… who is white.

In Parting Gifts, Barney says, “I don’t think he’s tracking me down to tell me I won Publisher’s Clearing House.” This is a reference to the multimillion dollar prize made famous by Ed McMahon.

When Angel is asking the Oracles to bring Doyle back in Parting Gifts, he reminds them that they changed time in I Will Remember You:
Male Oracle: “You try our patience. What is done…”
Angel: “…cannot be undone, you keep saying that. But I need Doyle. You …

The Ramsey Hotel scenes in Parting Gifts were actually shot at The Ambassador Hotel in los Angeles.

The hotel was a landmark in the city and the site of many Academy Awards ceremonies. The hotel and it’s nightclub, the Cocoanut Grove, were favoured by many Hollywood stars including Marilyn …

Cordelia says in Hero, “He’s a larger than life character, way too Braveheart for Joe Couch Potato to relate to.” This is a reference to Mel Gibson’s film about William Wallace.

The pier that was used for the scenes with the ship in Hero was at Southwest Marine, in Sanpedro/Long Beach, the Port of Long Beach.

Brachen demons have red eyes, spiked greenish skin, and are very strong. They are also reputed to have a good sense of direction. One of the clans lived in Oregon woods for a time. Doyle’s father, whom he never met, was a Brachen demon, making Doyle part-demon too.

The following conversation was cut from the Angel episode I Will Remember You. It references the Buffy episodes Surprise, Innocence, Becoming (Part 2), Faith, Hope and Trick and Graduation Day (Part 2):

Doyle: “So Buffy and Angel? It’s always been pretty volatile?”
Cordelia: “That was nothing. One time they kicked …

In I Will Remember You, Doyle says “Orson, we’re in a situation here!” This is a reference to the TV show Mork and Mindy, starring Robin Williams, in which Mork reported to his leader Orson.

We see in I Will Remember You that the Book of Kelsor says Mohra demons are assassins who take out warriors on the side of good. They need vast quantities of salt to live and their “veins run with the blood of eternity”. If they’re killed, they regenerate …