A great thread YoUhimER. I've always thought of such discussion and how a c-pillar could give cars a whole new look.
As for the ones u mentioned, I totally agree for the CL & Phaeton cases. As for the 3er, It is really dependant on the angle ur looking at the car from, to me all BMW's with their hofmeister kink suffer from a weak angle which is the front 3/4 angle. I've always hated that angle on BMWs.
well, C-pillars I like
New + old CL (Pic above)
Phaeton
Phantom 
Ferrari 599 GTB Fiorano
Aston Martin Vantage V8
I ll think of more later