Looking for some advice on family travel next May from Lugano, Switzerland. We'll be in Lugano for two nights for my daughter's college graduation. Then, we have six nights we can spend somewhere. Also have Marriott points to use & platinum status, so want to stay with the Marriott brand.

I was thinking we could fly from Milan to Barcelona for a 3-night stay there, then continue on to Lisbon for the last three nights. EasyJet flies Milan-Barcelona, Milan-Lisbon & Barcelona-Lisbon. So, that should work. (there is a van shuttle from Lugano to the Milan airport) Would you recommend 3 nights in each city, or is that the right amount of time in each place? Also, would you recommend going to Barcelona first, then to Lisbon, or should we reverse that order? Or, should we just go to one city, not both?

Which Marriott Hotels would you recommend and why?--any comments on upgrades, hotel location, amenities, etc. would be much appreciated. Traveling with two twenty-something-aged children who will want to enjoy the nightlife, beaches, etc. Also looking for something truly memorable and luxurious....thanks for your help!