Saw this on Guild Wars Guru forums and figured it's a good thing to know.

Emote Command Text Shown
/afk No text shown. (a)
/agree 'your character name' agrees. (a)
/attention 'your character name' comes to attention! (a)
/beckon 'your character name' beckons. (a)
/beg 'your character name' begs. (a)
/boo 'your character name' scares you! (a)
/bored 'your character name' is bored. (a)
/bow 'your character name' bows. (a)
/bowhead 'your character name' bows his head. (a)
/catchbreath 'your character name' stops to catch his breath. (a)
/clap 'your character name' claps. (a)
/cheer 'your character name' cheers. (a)
/chest 'your character name' butts chests with you.
/congrats 'your character name' offers congratulations. (a)
/dance 'your character name' starts dancing. (ca)
/doh 'your character name' smacks his head. Doh! (a)
/doubletake 'your character name' does a doubletake. (a)
/drum 'your character name' plays the drums. (ca)
/excited 'your character name' is excited! (ca)
/fistshake 'your character name' shakes a fist angrily. (a)
/flex 'your character name' flexes. (a)
/flute 'your character name' plays the flute. (ca)
/goteam 'your character name' cheers wildly, "Go Team!" (a)
/guitar 'your character name' plays a mean air guitar. (ca)
/help 'your character name' requests help! (a)
/highfive 'your character name' says, "High Five!" (a)
/jump 'your character name' jumps. (a)
/kneel 'your character name' kneels. (a)
/laugh 'your character name' laughs heartily. (a)
/moan 'your character name' moans. (a)
/no 'your character name' says, "No." (a)
/paper 'your character name' plays paper, rock, scissors.(a)
/pickme 'your character name' says, "Pick me!" (a)
/point 'your character name' points. (a)
/ponder 'your character name' ponders the situation. (a)
/pout 'your character name' pouts. (a)
/ready 'your character name' is ready for action! (a)
/roar 'your character name' roars. (a)
/rock 'your character name' plays paper, rock, scissors.(a)
/roll # 'your character name' rolls x on a # sided die.
/salute 'your character name' salutes. (a)
/scissors 'your character name' plays paper, rock, scissors.(a)
/scratch 'your character name' scratches. (a)
/shoo 'your character name' shoos you away. (a)
/sigh 'your character name' sighs. (a)
/sit No text shown. (a)
/sorry 'your character name' apologizes. (a)
/stand No text shown. (a)
/taunt 'your character name' makes a rude gesture. (a)
/violin 'your character name' plays the violin sadly. (ca)
/wave 'your character name' waves. (a)
/yawn 'your character name' yawns. (a)
/yes 'your character name' says, "Yes." (a)
/age special *
/deaths special **
/health special ***


Emotes with (a) after the shown text are emotes that currently have character animations. Those with (ca) or animations that loop. All other emotes show no animation, they only display the text.

* /age shows the amount of time you have played your character in hours and minutes.
** /deaths shows the number of times that character has died.
*** /health shows you your current health and energy out of your maximum health and energy.