I don't like to miss any European port. Last time to Palma we went to Soller and had a great day. We are scheduled to be there in August and will probably just wander in the old part of town. In Marseille we have gone to Provence, also a great day. Cinque Terra is awesome. Rome is Rome, I could go every year. Same for Amalfi Coast. That said, I would say the weakest is Palma.