Being one of the few people that has owned both, I would say that for me the Golf is a better car but it depends on your requirements.
Test both and get the one that lights your fire.
Beware though, Scirocco has long low doors so getting in and out of it in the supermarket car park etc is more difficult, Rocco isn't made in Wolfsburg and built to a lower spec (e.g. old school manual bonnet support strut) and you could fit an extra car in the huge gap VW have left between the tyres and arches so they only look OK lowered IMO. Contrary to what you might think, I would say the golf is a better handling car, Rocco suffers from understeer and torquesteer (on the GT2.0 that I had) and is no way as composed as the golf.