I'll start, if some are in game apologies:
Bowing
Waving
Kneeling ( which non RP people love to use for tea bagging fallen opponents)
Handshake
Cheer
Toast
Bend Over (used a lot, trust me)
Roar
Laughter (multiple versions)
Scouting ( hand above eyes looking)
Salute (multiple versions)
Point
Quiet (ssshhh sign)
Slit Throat (finger across throat)
Kiss (of course)
Blow kiss
Hug
Clap
Weapons in the air
...
Perfect for this game (and tell me guilds in siege/ war you do not want this option):
Braveheart 1 ( Bend over and expose your ass beneath your gear)
Braveheart 2 ( lift your frontal gear up and expose your privates)
Ok I Started...