What you should think about, is having an Classic of both brands. If you have a 70s Ferrari, people will think you have a moustache, curly hair and a hairy chest with an open pink shirt, even if you don't.Leaving quality out of it, just talking about coolness - its Aston.
The girlfriend's parents thing is very true: Ferrari's are obvious, ostentatious, and largely bought by people who don't appriciate it as a machine, but as a status symbol. New Bentleys have the same problem - their customers. Having an Aston takes a modicum of car knowledge. I also think it says something that hard edged performance and bright colors are sacrificed for a (comparatively) luxurious British racing green GT car whose badge doesn't instantly evoke thoughts of frivolously blown mega-wealth.
That said - Ferrari's are an engineering masterpiece beyond compare.
Concerning the Enzo - I don' think any cars that approximate the look of F1 cars are cool. (See F50, SLR, and SLK)
I love older Astons, the DB7 is probably one of my favorite cars of all time. Hell, i even loved the Vanquish.You DO NOT want to come driving in a Ferrari to your girlfriends parents the first time you meet them. They'll think you're a burk.
You come in an Aston, let's face it, everybody - unlike bartboy9891 anyway - loves an Aston.
My vote goes to Aston Martin. It's the only brand that is not ruined by who drive them. It's like a very nice girl with a bad boyfriend. No matter how the guy speaks and behaves, you won't go round saying "She's so lame". Right.