I honestly have loads of Fantasy and historical stuff to work on at the moment, but I’ve been drawing my plans for AoS.
Order: I’ll give you 3 guesses (clue: look at my avatar and many of my posts)

. I love my Lizardmen in Fantasy, but I just can’t get with the exploding into stardust and hordes of Skinks competitive mechanics of the AoS version. I also have Dwarfs and High Elves as Fantasy armies, but the former has been subsumed into the AoS version of the Empire and the latter’s been executed.
Chaos: Skaven, partly because I play them in Fantasy already and they are pretty much the same in AoS so don’t need to spend much more to get them battle-ready, partly because they are just hilarious all-round (don’t tell my Lizardmen army that).
Destruction: Gloomspite Gitz, for the same reasons as Skaven.
Death: Before AoS my favourite undead army was Tomb Kings, and I was really annoyed when they got squatted in favour of Vampire Counts/Legions of Nagash. Nighthaunt and Flesh Eater Courts also are more Vampire Counts oriented, so while the Ossiarch could have been better, I think they would look good once I’ve got my paws on some of them and Egyptified them a bit more.