One time, a friend and I were playing SSB64. Every Pokeball he got that match was either a useless/easy to avoid Pokemon, or Clefairy copying useless/easy to avoid Pokemon. Late in the match, he hit me off the stage and a Pokeball spawned right beside him. It produced another Clefairy.
Thinking that it was going to be another useless Clefairy, I very sarcastically said "Oh nooo!" As my character returned to the stage, Clefairy (copying Hitmonlee) launched itself and hit my character, causing a KO. We couldn't stop laughing.
Another time, we and a third friend were playing Melee. The two of them were DK, I was Kirby, and we had the computer on (not as DK or Kirby, thankfully). At one point in the match, I had copied a DK, and then was ganged upon by all three of them. There had been a lot of Bob-ombs spawned during that match. They didn't realise that a Bomb had spawned right under our feet as they were pummeling me. I made to get away, and hit a Party Ball. It happened to be a Bob-omb party.
Noticing that, I say "Monkey's! They're everywhere!" One of my friends said "Monkey's are everywhere?" Then started laughing. The comp player was already out, and there was the three of us: two DK's, and a Kirby Kong. Monkeys were everywhere.
Another time, the one friend (from the first story) and I were playing Brawl. He was picking up food from a Party Ball when a Bob-omb spawned beside him. He'd been hitting the button to get the food, and also picked up and threw the Bomb, causing himself to KO. He'd also said something like "Food! Not food!" as it happened.
Good times. :)