Of course I don't actually recommend taking girls to clubs as most clubgoer girls are slutty gold diggers.
Of course there are as many types of dance clubs as there are girls...

Such a car must be a 4-seater since your new girlfriend will ask you to take her sexy friends with you.
The 4 seater requirement excludes all sports cars. Most 4 doors are ugly (except for the Rolls Royce Phantom) so you must choose sexy coupes?
It must be flashy. It doesn't matter if it is fast, expensive or reliable. It must be flashy.

So depending on where you live
For Europe and some developing countries
- Late model Camaro. Specially the convertible version.
- Mercedes Benz CLK
- BMW M5 or at least M3 again convertible is preferred
- Audi A5 or A6 coupe