Suzuki GSX-R/4: Racing for A-Spec points, I've been using it pretty heavily - love the way it handles on racing tires.
Imprezza Super Touring: I've always enjoyed the feel of this one... just seems to fit my driving pretty well.
787: For top end cars, unfortunately I haven't spent much time with them, but the 787 has been pretty friendly so far.
M3 CSL: A more subjective preference - haven't won much of anything in it, but a sentimental favorite.