LX6 and FZ5 on anything.
LX6 and FZ5 are amazing in one respect to me; you don't have to be good with them to have an insane amount of fun on any track yet they are such different cars handling wise.
I equally enjoy the heaviness of the FZ5 as I do the lightweight+power+twitchiness of the LX6. Everything else feels a bit detached to me, with the obvious exception of the XRG...but thats engraved from "back in the day" demo days as well as CTRA.