I got some 18s (Conti SS Ultra) real cheap from Performance on a blow-out sale. I actually got a third tire in case one blew out the sidewall, they're so skinny. I've had very good service with these. They're very comfortable even at the rated 150 psi, ride and corner great and wear like iron.

I have had a couple of flats with these but not near as much as i thought I would have.