Oud is definitely my favorite. One of the cool things about it is that there are so many different varieties, so it is possible to wear nothing but oud and still wear a different scent every day of the week. Indian, Cambodian, and Indonisian varieties are some of my favorites.
The best oud I've smelled is from Oriscent (www.oriscent.com). There might be oud of the same quality elsewhere, but it would be difficult to find better quality oud, even for much higher prices. The difference between cheap oud and higher quality oud is clear. The good stuff can get very expensive, but there is nothing else like it if you are a fragrance connoisseur.