There are pros and cons of every colour, IMO:
Black
Pros - sexy; mysterious; stealth
Cons - hides a lot of the car's curves/lines; diffuser/grilles no longer stand out; is HELL to keep clean; very unforgiving to incorrect washing/buffing techniques; is a bit old-hat in 2012
Red
Pros - eye-catching; sexy; exotic; looks great in photos
Cons - looks cheap and tacky in real life; more liable to fade; unless it's a Ferrari, don't buy a red car.
Silver
Pros - smart; elegant; mature; safe choice
Cons - usually associated with owners who aren't passionate about their cars; underwhelming
White
Pros - so hot right now; elegant; prestige; makes the car look more expensive than it is
Cons - can be perceived as boring, no personality; hell to keep clean
Orange
Pros - eye-catching; different
Cons - polarises opinions; may not have a very long "shelf-life"; you may want to sell it in 6 months
Dark Blue
Pros - same as black
Cons - underwhelming
I've ordered the GTS in white, so of course white is the best colour
