I’ve been to Olbia area twice, a good base to do Costa Esmerelda, La Maddelena which are must visits and can even do a day trip across to Corsica from there
we've also been to Alghero which is a beautiful old town and some really good agritourismos to eat at dotted about
the local wine, Vermantino is beautiful and cheap and the Sardinian traditional meal Is suckling pig which is absolutely delicious.
best thing to do is hire a car and drive round the beaches are clear blue water and white sand and you’re only a half hour up into the hills. Loads of really nice little towns as well.
weve not done the south yet but will be soon