I think better of Poison. Now that it covers Fairy. Never had a poison move on any pokemon in the past. Didn't see any need to with it just covering Grass in past Gens. Now I'm going to put Sludge Bomb on my Gengar to cover those pesky Fairy types.
Though I'm still early in the game. Got it about 3 days ago.
"There is good in this world, Mr.Frodo.....and it's all worth fighting for." Samwise Gamgee in Lord of the Rings: The Two Towers