CKII is probably my favorite Paradox Game as to date, there are a few things about it that bugs me (such as how they decided to handle ships), but otherwise I still play regularly. The vanilla campaign has gotten loads better, but I still prefer to play w/ mods such as Lux Invicta, SMWH, and CK2+. Lux Invicta adds just craziness to the game, a lot of anachronisms and religions-- SMWH plays pretty similar to vanilla but adds a bunch of new provinces to the map, and CK2+ adds a bunch of extra content and improved playability. You can find these mods at the Paradox CKII forums, but you have to register a new account and your game in order to access additional content, but definitely worth it.