Ezreal vs Vlad - Both trying to be most effeminate man in the league.
Warwick/Nasus vs Nidalee/Rengar - Dogs hate cats.
Nidalee/Rengar vs Twitch - Cats hate mice.
Swain vs Fiddlesticks - Crow vs Scarecrow. Obvious.
Jax vs Zed - Jax appears to be a ninja turtle (my guess, Donatello) and Zed is CLEARLY the Shredder.
Gangplank/Miss Fortune vs Shen/Akali - Pirates vs ninjas.
Veigar vs Lulu - They both want to have the most oversized hat.
Teemo vs Teemo's Self-respect - Look at his skins and tell me he's not losing this one. Hard.
Cho'Gath vs Jayce - A space marine vs a Tyranid carnifex. Dur.
Kha'zix vs Kennen - A scyther and pikachu respectively. They don't wanna fight, but their trainers do.
Maokai vs Warwick - Mao is sick of being peed on.
Darius vs Karthas - Over who's ult is considered most annoying/cheap/no-skill/OP.
Master Yi vs Kassadin - Yi has a jedi skin. Kass looks like Darth Vader.
Karma with the Meta - And it seems she'll never find a place in it.