So far, I've added Silver Project camber plates and 26mm torsion bars in the back. When I bought the car, it already had a strut brace up front, 7/8" front sway bar and 3/4" rear sway bar.
The one big thing I did was ordered KW V2's. Tire Rack here in the US had them on their website, while not in stock, they were cheaper than anywhere else, shipped from their Nevada (NO TAX!) warehouse once they got them in, and all at no shipping cost to me, I was stoked!
Untitled by
Conner Kuhns, on Flickr
I have the front's installed already, but haven't gotten a chance to throw the rears on.