Ferrari. I like the styling, design, and overall concept better. I know Lambo has changed now that Audi has taken it over, but IMHO they're still more show than go. The focus of the car is about making a statement, being eye catching etc. And that's just not what I'd like in a supercar.
Specifically, I'd take an F430 if I had to pick a Ferrari currently in production. My choice of any Ferrari... would be rough, but I would have to say the 360 Challenge Stradale.