Wing 1: Thaurissan is pretty much used all over so you'll want him. quick shot fits into a lot of hunter decks. Grim Patron is pretty much the deck to beat right now, so there's a lot of value here.
Wing 2: druid of the flame if Beast druid gets off the ground with TGT? Lava Shock if TGT cards make it worth running. Imp Gang boss works out in Zoo and some demon based decks. Blackwing Tech is a great Dragon synergy card so you'll want that if you're running dragon decks. Wing 2 is okay but more niche, the legendary is garbage tier.
Wing 3: There's Dragon Consort for Dragon paladin and maybe Twilight Whelp for Dragon Priest (sort of iffy). Also Rend for Dragon decks. Pretty weak wing overall.
Wing 4: Flamewaker is sweet for tempo mages, Fireguard Destroyer is quite good, and then you get chromaggus.
Wing 5: Dragons dragons and more dragons, the big pickup here is blackwing corruptor for your dragon decks, and then Nefarian as a big dude that gives you sacrificial pact for trolden videos (also he's a dragon).
Wing 1 is huge, Wings 2 and 4 are pretty okay, wing 3 and 5 are sort of niche and only useful for running dragon decks.