Welcome to the Hellmouth/The Harvest

Xander: "I kind of had a problem with the math." 
              Willow: "Which part?" 
              Xander: "The math." 

Xander: "Can I have you?" 
Buffy: "..." 
Xander: "Uh...can I help you?" 

Xander: "We both go to school. Very suave, very not pathetic." 

Xander: "I don't like vampires. I'm going to take a stand and say they're not good." 

Xander: "I mean, the dead rose! We should have at least had an assembly." 

The Witch

Xander: "I laugh in the face of danger, and then I hide until it goes away." 

Xander: "For I am Xander, King of Cretins. May all lesser cretins bow before me."

Xander: "First vampires, now witches. No wonder you can still afford a house 
in Sunnydale."

Teacher's Pet

Xander: "Those who can do. Those who can't laugh at those who can do." 

Xander: "Forgiveness is my middle name. Well actually, it's Lavelle." 

Xander: "What kind of a girly name is 'Angel' anyway? 

Xander: "I love Buffy!"

Never Kill a Boy on the First Date

Xander: "So Buffy, how'd the slaying go last night?" 
              Buffy: "Xander!" 
              Xander: "I mean, how'd the laying go last night? No, I don't 
              mean that either." 

The Pack

Xander: "I've been waiting for you to jump my bones."

Xander: "Shoot me. Stuff me. Mount me." 

Angel

Xander: "You know, I don't know what everyone's talking about. That outfit doesn't 
make you look like a hooker." 

Xander: "Buffy, come on. Wake up and smell the seduction!"

I Robot, You Jane

Xander: "You're going to be missing out. I'm planning to be witty. I'm going to make
fun of all of the people who won't talk to me."

Xander: "To read makes our speaking English good." 

The Puppet Show

Xander: "Can I just mention that detention is a time-honored form of punishment."

Xander: "Did I mention that I hate this school?" 

Xander: "Redrum! Redrum!" 

Xander: "So the dummy tells us that he's a demon hunter, and we're like, 'Fine.  
La la la la.' He takes off, and now there's a brain. Does anybody else feel like 
they've been Keyser Soze'd?" 

Nightmares

Xander: "I'm not worried. If there's something bad out there, we'll find, you'll
              slay, we'll party!" 

Xander: "I'm sorry. I'm unruffled by spiders. Now, if a bunch of Nazis crawled all
              over my face..." 

Out of Sight, Out of Mind (Invisible Girl)

• Season Two: When She Was Bad through Ted
• Season Two: Bad Eggs through Becoming
• Season Three: Anne through Amends
• Season Three: Gingerbread though Dopplegangerland