I've never been much of a PvPer so this expansion has been a lot more open for new people to step into it which I enjoyed.
Currently just pushing into Heroic Antorus, I've been playing WoW since early TBC but never really been quite good at it so this expansion has probably been the first time I've put this much effort in.
Favorite Faction: Alliance
Favorite Races: Lightforged Draenei, Belf, Mag'har and Zandalari eventually.
Favorite Classes: Warlock (Destro), Ele Shaman, Frost/Blood DK.
Favorite Expansions: WOTLK for the story, BC for the overall experience.
Favorite Dungeons: Old SF Keep, BRD(when it wasn't broken into pieces), Old Strath, Old Scholo. ToTC, PoS,
Favorite Raids: Zul'Aman(BC), Sunwell, Black Temple, Ulduar.
Your Realm: Khaz Modan / Aggramar
edit: Changed the questions so that it makes sense to add in multiple answers.