A while ago, an online bellydance community called Bhuz had a thread in which the members nominated songs they felt all bellydancers should be familiar with. I compiled an initial list of songs from that set of conversations, talked it over with some other dancers, and eventually came up with this list. Whether you are trying to build a dance music collection, want to guess what a band might have in store for you, or just want to listen to a popular selection of bellydance tracks, this list might be helpful.
Notes on shopping for bellydance music: Songs with Arabic titles might be rendered into English in many different ways. Hes Bes might be Hoss Bass; Betwannes Beek might be Batwannes Beek. You might have the most success shopping online at a store that provides a lot of mp3 clips and a really good search engine. Clips are important because the style of a classic tune might not be what you expect. Alf Leila Wa Leila on qanoon and tabla sounds quite different from the same tune fully orchestrated. Do you want the version of Enta Omri with a vocalist, or only an instrumental? Do you want the 40-minute live recording of Zay al Hawa with Abdel Halim Hafiz, or the 7-minute version by the Cairo Orchestra?
These lists are by no means definitive, simply a place to start. Listen to all the bellydance music you can; greater musical knowledge will help your dancing.