Buffy the Vampire Slayer/Recap/S5/E03 The Replacement

Xander: I'd like to see you handle having an evil twin!

Willow: I handled it just fine.

A demon accidentally fires something into Xander which creates a Xander clone.

Acting for Two: Averted as the second Xander was played by Nicholas Brendon's real-life identical twin, though Nicholas would play the main speaking role in each scene.
An Aesop: Xander realises his inner potential. Again.
An Axe to Grind: Buffy in the garbage dump.
Applied Phlebotinum: Toth's "creepy stick thing", the ferula-gemina. "It splits one person in half, distilling personality traits into two separate bodies."
Artistic License Gun Safety: Averted; Xander unloads his pistol before handing it to Buffy.
Badass Long Robe: Toth

Buffy: He ran away, huh?

Giles: Um, sort of more ... uh ... turned and swept out majestically.

Butt Monkey: Scruffy!Xander
Call Back: Willow, to the events of Doppelgangland, relating to the similarities and contrasts with the current episode.

Willow: Xander. You already knew that he was taking over your life, and you didn't think of Anya until just now?

Xander: Hey, you wait until you have an evil twin. Let's see how you handle it. (Exits)

Willow: (Bemused, to herself) I think I handled it just fine.

Captain Obvious

Buffy: If Xander kills himself, he's dead. (frowns) You know what I mean.

Continuity Cavalcade: Riley is helping Xander leave his parent's basement forever.

Riley: Getting nostalgic?

Xander: I don't know. At first it's just a place, then you start to make memories, and ... then you're like, (pointing) that's where Spike slept, and (pointing) there, that's where Anya and I drowned the Separvo demon. Oh! (points) and, and right there, that's where I got my heart all ripped out. (shakes head) I really hate this place.

Damned By Faint Praise

Xander: But I never help. I get in trouble and Buffy saves me.

Willow: That's not true! Sometimes we all helped save you. (realizes that was unhelpful) And sometimes you're not in trouble.

A Day in The Limelight: This applies to Xander twice over!
Deadpan Snarker: Joyce shows that It Runs in The Family.

Dawn: Mom, I can stand in the hallway, right?

Buffy: She's watching us [Buffy/Riley smooching] like a big freak!

Joyce: (sighs, puts hand to her forehead) This must be my "two teenage girls in the house" headache. I thought it felt familiar.

Buffy: Good work, Dawn. You gave her a headache.

Dawn: I did not! (to Joyce) Did I give you a headache, Mom? I'm sure part of it is Buffy's.

Buffy: But part of it is Dawn's.

Joyce: It's so nice you've learned to share.

Description Cut: Willow re witch cliches. "Who uses a cauldron any more?" Cut to the demon using a bubbling cauldron for his incantation.
Did Not Do the Bloody Research: In Universe -- Buffy assumes that "Toth" is British for "moron".
Empathic Environment: It rains on Xander when he goes to get Buffy's help, only to find his other self has got their first and Buffy is fixing to kill him.
Evil Twin: Suberted
Eyes Never Lie: Averted; Anya can't tell the difference between the two Xanders, despite Scruffy!Xander's plea.
Get a Room: Xander opens a door in his new apartment to find Buffy and Riley making out. He tells them to go find a bedroom, then realises they're already in one.
Hollywood Healing: Averted; Anya is still recovering from a dislocated shoulder, after being knocked down by Mort in the previous episode.
Hypno Trinket: Xander notices his Evil Twin carries a shiny coin that appears to change everyone's attitude towards him.
Improvised Weapon: Giles rummages in a box for something to ward off Toth. He finds a rabbit's foot, then a wooden statue.

Toth: That is a fertility god. (Giles looks at it in dismay) Feeble man, you are not going to distract me-- (Giles hits him with the statue)

Literal Split Personality: Toth's weapon was meant to split Buffy into her human and Slayer sides -- he would then kill the weaker human version, causing the other to die. Instead it seperates Xander into an "aggressive" Xander (charming, well-groomed, and confident; but hot-headed and impetuous) and a "passive" Xander (awkward, paranoid, and insecure; but with Xander's trademark sense of humor).
Martial Arts Do Not Work That Way: Buffy complains about the unrealistic fight scenes in the chop-socky movie.
Moment Killer: Dawn on the Buffy/Riley snog.

My friend Sharon's older brother knows a girl who died because she choked on her boyfriend's tongue.

Oh Crap

Giles: Oh dear Lord. (Scoobies keep talking among themselves) I said, "Oh, dear lord."

Buffy: You always say that.

Giles: Well, it's always important!

Pop Cultured Badass: Buffy's "bad ice-skating movie obsession".
I Say What I Say

Buffy: What if it doesn't work?

Xanders: Kill us both, Spock!

Willow: They seem more normal now.

Giles: Yes, I think he's a bad influence on himself.

Red Herring: The shiny coin the other Xander carries isn't used to hypnotize people, it's just a trinket. Also Spike's dummy appears to be about him plotting to kill Buffy, but it's actually Foreshadowing his obsession with her.
Shaped Like Itself: "It's an evil robot, constructed from evil parts that look like me designed to do evil!"
Shirtless Scene: Our first sight of Suave!Xander.
Shout Out: When they try to put the two Xanders back together.

Anya: What do we do if this doesn't work?

Both Xanders: Kill us both, Spock!

Spot the Imposter: Xander does the Snoopy dance to prove he's the real Xander. Willow is rather confused, as she doesn't even know there's two Xanders walking around.
Suspiciously Specific Denial: Not that Xander is still into Buffy -- not that he ever was.
Taking the Bullet: Xander gets hit by Toth's magical blast when he shoves Buffy aside.
Twin Threesome Fantasy

Anya: So... you Xanders really do have all the same memories, all the same... (looking downward) physical attributes?

Suave Xander: We're completely identical.

Scruffy Xander: Yeah, we checked out some stuff in the car on the way over... (off Anya's look) Fingerprints!

Anya: Well, maybe we shouldn't do this reintegration thing right away. See, I can take the boys home, and... we can all have sex together, and... you know, just slap 'em back together in the morning.

Suave Xander: She's joking.

Scruffy Xander: No she's not! She entirely wants to have sex with us together. Which is... wrong , and, and it would be very confusing.

Anya: It's not like it'd be cheating. They're both Xander.

Wham Line: "But she doesn't love me".
What Do You Mean Its Not Heinous: One look at the dump and Riley continues to lose faith in humanity.

Riley: People say they're recycling. They're not recycling.

Your Door Was Open: Lampshaded when Willow bursts into Giles' place.

Giles: I swear, this time I know I had that locked.