my mums from sardinia and so i am clearly a bit biased but i can honestly say in my opinion it is the nicest place in Europe to go for a quiet beach holiday. Absolutely beautiful beaches, almost guaranteed warm weather, warm people, great food, cheapish if you stay away from the hotspots. Brilliant roads for motorcycling too if you're into that. Only problem is that more and more people from Britain are finding out about it every year!
I went there a couple of years ago. It was lovely. Agree with everything geff says. Only mistake we made, was visiting when it was the Italian Bank Holiday, so everywhere was packed. And our accommodation worked out very expensive.