Given the options you have the choice of, I'd take the Scirocco.
It's a great looking car, great to drive and the 170hp Engine is as good as it gets when it comes to offering decent pace and economy.
The Golf GTD is by no means a bad car - in fact I think very highly of it - but if you don't need the practicality of the 5 door hatch then there's not much else to gain by getting the Golf over the Scirocco.