Hmm. Tangier is nice if you can handle hustlers and are a beach girl. It's also nice if you want to go to europe since it's just across the water. If you want a more exotic experience then i would recommend some other place like marrakech or fes. although fes is more conservative so it all depends on your lifestyle. in my opinion marrakech has the best of everything but it is touristy like most of the major cities. casablanca is quite polluted and not the safest of the cities. i leaving the airport (w/locals) in the middle of the night and got attacked by theives - they threw a huge rock through the car window. nothing happend to me on other trips to casablanca but it definitely isn't the most charming city. so most important is to decide what appeals to you about morocco and what kind of lifestyle you have - then it would be easier to recommend a destination. tangier doesn't have a lot to see, it's best for the beach lover.