It really depends how much you want your car lowered, how much you want to spend, and how important ride quality is. Below is a quick summary. The link at the bottom has more info.
Springs lower your car about 1.5 in, cost between $200-$250 and "typically" give you the best ride quality. May require a camber kit depending on setup. I don't have one.

H&R

Tein
Coilovers give you a drop around 3 in and cost between $700-$1000. Coilovers are "typically" a rougher ride than springs, but most come with adjustable damping. With a bigger drop comes more camber and higher likelihood of needing a camber kit.

Tein Street Advance

BC
Air ride obviously can dump your car, but costs $2000+ depending on the setup. I don't have any experience with ride quality of air ride setups.
I tried to get pictures with stock wheels to provide a decent comparison. You can always get bigger wheels to further reduce/eliminate fender gaps.
coilover-lowering-spring-options-t559823.html