Hi Bucky,
I'd tend to agree that the most intersting Megalithic Architecture was that of the Nuragic Bronze Age with the Nuraghe, well temples and Giants Tombs, however these evolved from Chalcolithic and Neolithic structures, cists and galleries so you can see a progression, an evolution of architecture on Sardinia.
I agree that most of the Neolithic sites are pretty run of the mill, cist cemeteries, dolmen and the rock-cut Domus de Janas. However I saw one site there that could be classified as unique to western neolithic Europe, the wonderful 'ziggurat' of Monte d'Accoddi.
cheers
Fitz