A few more popped into my head after our latest session...
"Pose": Describing your character's actions in full "theatrical" style. Also used in verb form as "posing" to warn everyone you're in the middle of typing said actions.
"It was nice knowing you": Standard response whenever someone fails a save badly or rolls a 1 on an attack roll. Though, ironically, we haven't had a PC die yet in two years of gaming (although we've come close several times).
"Can I have the 100-words-or-less summary?": Just what it sounds like, really. So formed after the standard wording on standardized essay tests and similar things. People will often try to keep their summaries under the limit, too, even IC, just to play along.
"Clanky McSlowspeed": Nickname for the cleric, or any other heavily-armored character.
"Degaussing": Rolling 100d20 or so after a string of bad rolls in an attempt to "clear out" the dice roller macro.
"Purple editing pen": I am the de facto secretary for my group; after every session I edit the OOC log to pull out funny quotes, and I edit the IC logs to make them flow more like a story.
So, whenever someone posts something at the wrong time, makes a typo, needs to redo an action, or otherwise messes up, I hear "Could you fix that in the logs?" a lot.
So I then wield my purple editing pen, colored in honor of the children's book Harold and the Purple Crayon.
Peace & Luv, Liz