H&R sport springs!

 

You can swap the aftermarket springs out with the stock set.
I currently have the Spec R's and I'm happy with them.

I believe the Eibach springs drop the lowest from reading around the forums and seeing them in person, although the H&R's drop is a close second for lowest drop.

 

I have K&W coilovers and they dropped my car about 1.5-2in at the most and I really like the way they feel in the corners

 

Coilovers are not springs - irrevelant post

 

Spec R's are a great choice for springs, we haven't had any customer complain. But if you want more of a drop there are other options. There are plenty of spring options out there so you should explore depending on your needs/wants.