My funniest moment is only funny to other people, I was playing Fiora, I had gotten super fed, and I took out the entire enemy team on my own save one. The final Trundal had one block of health and was in the spawnzone, I dived for him, I had full health, he had less than 10 health points left, and then a super-minion I had enabled broke the nexus. I shot out of my chair and ran into a wall cursing. It was so close to being a penta.
My funniest troll wasn't really a troll either, and it was me. I don't find trolls/trolling funny, but, when I started playing, my friends got me hooked and abandoned me to figure out how to play, I earned Kayle, and developed the following stratagy: charge the enemy fortifications and beat on them with my firesword no matter what, and ignore all enemies. It worked really well, until I wasn't playing against new players, then it fell apart. Then I learned to actually play.
Dinner and Ballgame: either Singed or Ziggs, they're both really smart so they would be interesting to talk to, Ziggs is hyperactive so he would be funny. Assuming ballgame refers to baseball, Ziggs would be hilarious, because baseball is Boring. As. HELL., so he would get antsy, and Singed, being so knoladgeable with chemestry, could intsantly spot all the players on steroids, which would be fun for me, since I don't like sports or atheletes.