My friends and I laughed so hard playing Brawl. We would do all kinds of stupid stuff.
Once one of them and I were both Snake and he gets the Smash Ball. He jumps offscreen and right as he comes back down to shoot grenades at me I do the taunt, which is of course hiding in the box. He laughs and says "WHERE'D HE GO" like a genome soldier and waits or Snake to come out from under the box, then does the ! sound and kills me, lol.
Another time it was a three-man free for all brawl and I choose Bowser, pick one of the friends and suicide him to death on every single stock. He raged, but my other friend was obviously happy to win.