G37 has a much nicer interior than the G35 and the Z is 3rd IMO. The G37 has the best engine of the bunch by a long shot. If I wasnt so far into my G money wise i would have a new G37 this winter.
Dont make the mistake of compairing the G37 and the G35 the G37 is a much more refined car. But like I said the styling is personal prefrence just something for you to think about.