Well - I like all wheatears, chats and alike. I also really like black and white birds, so that combined with a wheatear is great! The 2 species in Morocco that fit the bill are Mourning and White cround wheatear. We were lucky enough to see both!
White crowned were very common with tens seen on most journeys through the stoney desert areas but mourning was rather hard with only 2 seen in total...
White Crown Wheatear: