I lived there in '98 while my parents were teaching at Al Akhawayn University, and went back in '06 (actually stayed on campus in the building next to where we lived) for a three week study abroad.
Meknes is the wine producing capitol of Morocco. They do some very nice Cabs, and other reds. Check out the old granary while you are there. Volubilis is a great Roman ruin with well preserved city layout and mosaics. Fez has one of the best Medinas (old cities) along with Marrakesh. Rabat and Casa are relatively less interesting than a few of the other cities but both have some great palaces to visit. Both are very modern and huge economic engines for the country. Tangiers has always been a little dangerous, being a port city right next to the Rif mountains (yes, that's where that term comes from) which are pretty much an autonomous region controlled by the local warlords. Visit the Rif at your own peril.
Essaouria and Agadir along with southern coast are beautiful beach cities, with their walls overlooking the ocean. There is a castle turret on one of their beaches (sorry it's been 15 years) that is purportedly the inspiration for Hendrix's "Castles Made of Sand" while he was living in Agadir.
Plenty more recommendations as to where to go, feel free to message me if you are still there.
Bring back a tajine and a cous-cous serving bowl if you have the luggage room. They make beautiful, and functional wall ornaments, and a clay tajine is the only way to really get the same results (curse you physics). Rugs from the Atlas are generally the best, and frequently cheaper than in the major cities. Woodwork and Silverwork from Essaouira is spectacular, but anywhere else you can find some great stuff. Cedar work specifically from the High-atlas is marvelous (Azrou).
Hope you are still there. If not, I hope you enjoyed your stay and are planning your next return trip!