Thanks guys!
Turtle Life, Casablanca is the most happening city (partying etc), but I have a hard grasp of the city. Rabat is the best city for street skating together with Agadir. Fez isn't much of a skate city, but it's quite nice. Just don't let the locals trick you out of too much money (for showing you the tanneries or just helping you find a location in the medina.) Marrakech should have some spots and cool places to check, but I don't know too much about the city.
Hope you have a good time around there.