Fun question!
I agree with a lot that has been said (except SD987's
)
I love how the convertible tops folds neatly into the back, and looks very "finished" when the top is down. The whole "lowering the top" process is pretty cool to watch. I think when people see it, they are kinda amazed.
Another amazing feature of the Boxster was the 60 page ordering guide. You can really customize the car to be exactly how you want it.