I think it depends on how much time you have (since some are much shorter than other desert tours), on your budget, and on the interests you have. (arzotravels.com)
We hired a driver for a three - day desert tour to the Chilean border and when we crossed over, Ania and I took exploration into our own hands by renting mountain bikes. (theexpeditioner.com)
We also offer Marrakech to Fez luxury desert tours via Erg Chebbi, desert experiences that last 3, 4 or 5 days including an overnight in a luxury tented camp and the rest in boutique hotels. (ouarzazate-unlimited.com)