Sort of in order: The Old World stuff doesn't really excite me, although the tomb king looks fine.
The Sigmar knights are a cool look, some visual ties to the Empire from WHFB while still "feeling" like they belong in the grittier areas of AoS.
The Nurgle guy is awesome though, a great take on a classic model, crossed with that famous Frazetta painting. Excellent stuff.
Leviathan is Leviathan. The nothing-newness of the Marines is balanced nicely by the newness of the Nids, but like not enough to make me want to get any. We'll see if I resist the call of that pastel-colored Nidzilla army I was thinking about a few years ago as more models come out though, the big brain beast is right up my alley.
The plastic Knight is cool if you're into that! Cerastus are definitely edging up into "just play Epic already" territory though as far as I'm concerned. It does remind me I should get a box of Acherons and Castigators for AT though.
The WarCry terrain isn't particularly exciting to me but the ghoul warband looks pretty sweet:

Babhouls. Ghouloons. Something like that.