I've had several epic moments during a playthrough of Mario & Sonic At the Olympic Winter Games' Festival Mode (Damn, that's a mouthful) that I had with my friend. We'll probably never be able to replicate them. We were Silver, Vector, Amy and Tails.
We were playing Short-Track Relay. Our fourth player was Tails and he won the Relay. However, during the finish animation right before the victory pose, Waluigi came and creepily skated just inches behind Tails. He even had his long arms hanging around the two-tailed fox! It was so creepy and funny we bursted out laughing.
During Dream Ski Cross, I (Who played as Amy) left my team completely in the dust. I don't know how, but I somehow got really far ahead of the others.
During Dream Curling, we initially thought we made a really poor shot, yet somehow we got the stone to bounce around and knock down almost every bowling pin!
At the end of the Dry Bowser battle, we noticed in the background that Vector was peeking into the audience stand. None of us could resist the "Hi kids!" jokes.
Durng an Ice ahockey match, we got really nervous when I almost shot the puck into our own goal and when on of the enemies showed up to finish what I started. Luckily, our goalie (Tails) managed to block the puck.