The Nissa Planeswalker card that turns lands into creatures makes me chorttle.
Mainly because I have cards to destroy creatures at the ready :V
Killing the lands alone doesn't beat Nissa, you have to have a way to get rid of her as well. I've won games where all I had left after a wrath was Nissa and 2 lands. Eventually she is going to get to 8 loyalty and have a ton of backbreaking top decks with only a few lands left in deck, or she'll just generate enough mana to power out a huge jellyfish. People talk about baby Teferi and Narset as the most broken cards in WAR, but I think she's up there as well.