The Zombie brand is actually very well done. The other skins however seem kind of meh to me though. Maybe it's because I think Ryze was not in need of another skin, I hate Fiora, don't ever play TF, and don't like the skin for Maokai. While the Hecarim skin was interesting, the fact he's just a pumpkin head means I'll stick with the cooler looking reaper Hec which was recently on sale.
As always it's personal preference. Those that like the champion and want a cool halloween skin will pay. Most won't. Can't please em all.