I just picked up Supernatural last week and absolutely love it. The sheer amount of new content and new interactions adds so much to the richness of the game, and I love that you can turn off the various supernatural life states so you can still play a normal-ish town if you want. That plus the ability to halt the moon cycle (thus avoiding zombies!) is very convenient.
My favorite things thus far:
The new clothing. I think EA went above and beyond to create such creative and diverse outfits. Though...I do wish that the leaves on the child fairy outfit were recolorable.
Alchemy. You can vastly influence the town by tossing a few potions here and there, something which is a great advantage when playing a dynasty. Got a sim you want to hang around for a while? Turn him or her into a vampire or a fairy, then Potent Cure them later on, or just hit 'em with the fountain of youth elixir. In my test file I had my witch alchemist (Mortimer!) throw an opposite personality elixir followed by a fountain of youth elixir at Vita Alto to a very interesting effect. Vita is now younger than her daughter (temporarily--Holly is a fairy) and has the Good and Easily Impressed traits instead of Evil and Snob. The next thing I knew she and Nick were divorced and she was dating a werewolf Thornton Wolff! Talk about changing the dynamics of the town!
Gem-U-Cut Machine. A quick and easy way to get rich especially if you have a werewolf around to hunt for the good gems. Between that and the Midas Touch elixir and it's almost too easy to make money.
Fairies. The entire reason why I got the SN expansion in the first place. The interactions and animations are just adorable. The fairy tricks are just hilarious! I had Darlene Bunch torture her brother Arlo with Gold and Toads a few times--poor guy was coughing up gold for days.
Stuff I'm not all that enamored with:
Zombies. Yuck. Ew. Gross. I'm keeping the moon phase on waxing gibbous, thank you very much.
Pestilence Plague. Nice if you want to torture your sims, but the constant waking up with the coughing fits is irritating to say the least.
The Philosopher's Stone. Because the very first time I used it, THIS happened:
Thankfully Morty had a death flower (courtesy of his two fairy roommates) but still...the
first time? I'm not taking that chance again.
All in all this is my favorite expansion yet.
