Depends on what you use the car for. If you just want it for looks, 19s are fine, but you also need supporting mods. I have 16, 17, and 19s for the car. You can definitely feel a weight difference when driving the car.

lowered on espilar springs with Route KS half bumper, feel's side skirts, and gp sports rear.

 

He is right about larger heavier wheels slowing the car down and decreasing the top speed. I try not to drive over 100, because I can't afford another ticket.
So I have never "hit the wall" tht my new "heavy" 18 have created. They are on sale right now on tirerack for $99 and $109. KZ-K's.

If I could afford the 19" O.Z.'s on tirerack, they would be on my S2000.

 

The Ap2v2's look bigger then most 17's due to the lack of a lip.Also having the spokes go from edge to edge helps.When the inside spokes are painted black,with the machined spokes left untouched,look like 18's.

 

Great response! Thanks very much for the tips. I guess I will probably go in the middle and go for 18's (as light as poss)! Wheels do look far bigger when the spokes go right to the edge. I really like the 18" BBS LM, but they might just be outside my price range at the moment.

 

these are some sweet 18's and light as crap! but they arnt cheap either..

http://axiswheels.com/wheels.php?id=circuit

 

18X9 18X8 on my car....I wish I had bought some 17" Advans instead. Stick with 17s, its the way to go. The ride quality is awful with 18s