Oh, this thread is priceless...
I'm going to have to look up more stuff at home later, but here are a few of my favorites:
GM: "Don't you want to touch the statue?" (of a really repellent creature with too many, um, male enhancements)
Player of rogue: "No! It's gross!"
GM: "Don't you want to take the golden nipple rings?"
Player of rogue: "It has golden nipple rings?!"
Player of gnome druid, after wild shaping into a bat: "I'm Batgnome!"
Same player: "I poop on them."
The GM was making odd hooting noises while looking up something in the DMG.
Player: "This has been a test of the emergency DM system. Had this been a real DM..."
Player (after encountering hobbits on skewers being cooked by ogres): "Shishkahobs!"
Same game (there was a theme of eating hobbits):
GM:"The hobbits have bears stitched into their jerkins."
Player: "Stitched into their jerky?"
While fighting a water elemental:
GM: "What do you do?"
Player: "Anyone have a straw?"
GM: "The goblins attack with wardrums."
Me: "How much damage do those do?"
GM: "Well, they're wardrums, so d4."
Me: "D3 for size."
Other player: "Snare drums do entangles."
Player: "Is that a Bissell dragon - it sucks things up?" (for those who don't know, Bissell is a brand of vacuum cleaner)
Me: "You do NOT want to play Post Office with a mind flayer!"
[Edit: thought of another one] Player of halfling with 4 Str: "I'm tired. These limbs are heavy."
And my current fave: my sig line. It was a quote from a fellow player to a GM who got all bent out of shape when we did something he hadn't anticipated.
