One of my favorites came from the very first 3rd edition game I EVER played - at the RPGA Open back in 2000, "Finger of the Wind" at Gencon.
I played with 8 complete strangers, only one of whom I recall (Matt from Atlanta, but I couldn't tell you another darned thing about him.

) We played the "Greyhawk Iconics" (Mordenkainen, Robilar, Quij, Yrag, Bigby, etc.) trying to solve a mystery involving the Wind Dukes of Aaqa.
The woman playing Quij, I should note, was one of the most fun players there. I played Robliar, and it was like we had rehearsed the whole thing - Everything from Quij "loyally" checking for traps (which I sort of enocuraged) to giving Quij treats when he did something well. The jokes about "Quij Snacks" were great.
Amazing how a single spectacluar role can change a major battle to a non-event. One of the very first traps was a lever near the front gate. Like an idiot, I had Quij pull the lever to see what it would reveal. What it revealed was a tremendous alarm, obviously attached to the next door guard room. After a round or two of everyone trying to decide what to do, I decided in a flash of inspiration to burst into the next room, everyone following, and DEMANDED to know why the guards had not come sooner. I dressed down the guards (God help us, they were Vampiric Hill Giants!!) Told them the overlord was NOT pleased with them at all, and demanded an explanation.
An unskilled bluff check was called for - Natural 20, which with my CHA came to a 23.
Staring imperiously, I stared the giants down, they apologized, and we stormed in a huff past them to go meet the overlord. What would have taken a horrific fight took about 3 minutes of roleplay. Unfortunately, I had to bow out before the second round, so I don't even know how far our group made it.