This is sorta like the Funniest Brawl Moments thread, but here you can post funny moments related to any game, not just the SSB series.
My sister and I were playing Mario Kart 64. We finished our race and watched the award ceremony up to the point where the Cheep-Cheep was about to spit out the trophy. We agreed to turn the game off and play a different one. As the cable came on, there was this commercial on, and a man in it said "Man that's a really big fish!"
Another time, a friend and I were going to play SSB with stereo sound, but I couldn't figure out how to get the sound to run through the game, so we just left it alone. We turned the game on, and me, with my ADD, turned up the sound, completely forgetting that the game wouldn't be in stereo. Someone had been watching Cartoon Network, and suddenly Foghorn Leghorn's voice very loudly says "Woof woof!"