18's are hot but tires are more costly and you need to run a lower profile tire leading to more chance of F-ing your rims up. I run 17's now and most likely will go back to the stock SH wheels or a different set of 16's. When I switch in the winter back to the 16's the car feels much quicker. Besides the total weight of the wheel, the tire is much more weight on a 18 making the car slower.

For looks 18's, for speed 16's and 17's for the inbetween.