I have the opposite viewpoint from chelmkamp. I would prefer Bahrain; it has some of the glitz of Dubai, and much more vibrant nightlife than Doha, and also interesting local neighborhoods, souqs, and cultural attractions (little museums and cultural centers in Muharraq, for example).

These do not compare to the Museum of Islamic Art or Souq Waqif in Doha, for sure, but those are really the only two attractions in town, meaning that a half-day stop-over is enough in Doha unless you are a hard-core art enthusiast. Doha has better five-star hotels on the whole, but you can do fine in Bahrain -- the new Kempinski is as sophisticated as any offering in Doha, and the InterCon has been recently renovated (I haven't stayed there since then).

I also don't agree that three nights is not enough for Oman. Sure, you could traverse the country, from the tropical areas in the northeast to Muscat and on to Salalah and have a good time, but, given that there really isn't much to do in Muscat beyond the souq and the great hotels, I think that as a first-time visitor you can get enough sense of the country in three nights.