I have stayed at the following Marriotts in Europe:

Frankfurt Marriott
Monaco Marriott
Amsterdam Marriott
Capri Marriott
Rome Grand Flora Marriott
Zurich Marriott
Milan Marriott
Marriott's Club Son Antem (Majorca)
Marriott Champs Elysees, Paris
London Marriott Hotel Regents Park
Athens Marriott

There is no doubt in my mind that the Rome, Paris & Capri properties far outclass the rest of the ones I have stayed at.

Caltraveler