Nice list. The ISs are decent fun cars, I had a '06 IS250 (wanted the mileage) that ended up being a Lemon. Those issues have been sorted out on the '07.5+. The IS250 is slow, but handles rather well and is nice to drive. The 350 is actually relatively quick, and would have been a “fast” car like 5-10 years ago. The F gets into true fast territory.
That being said the CTS-V is the obvious pick off that list. It is in the dumb-fast for a 4 door arena, and out looks/handles/stops the others. The interior is subjective, but I really liked it (w/ the optional alcantra wheel and stuff) when I checked 'em out. I ended up going for a RRS SC because I wanted space and towing capacity otherwise I’d be in a V.
-TJ