Now then. I have a lot of experience with the Gulf Airlines.............
Basically it depends where you are going................e.g. If you're heading to Dubai first, then logically take Emirates. If to ABu Dhabi first, take Etihad. If you're heading to Qatar first, take Qatar Airways (these are the best in the region at the moment by the way).
Now then............if you are going to Kuwait first..........fuck Kuwait Airways off. They are shite an ddon't serve alchohol. So best take Emirates or Qatar and then get another flight from their hubs into Kuwait.
Same deal if you're heading to Saudi Arabia. However, there is not too much choice of flight times into Saudi because no fucker in their right mind wants to go there so you may be stuck with having to take Saudi Arabian Airlines (another shitty one with no beer!).
If you're heading to Oman..........take Emirates or Etihad to their hubs hen hop across the short flight on either those Airlines or Oman Air. Don't do long haul with Oman Air...........not that good. Short haul okay because they bought new 737-400's recently.
Now for Bahrain...............their airline is Gulf Air............it's shit! Take Emirates, Qatar or Etihad from the hubs into Bahrain.
Now for hopping between Gulf States, a few of them have their own low cost internet Easyjet type airlines. Kuwait has Wataniya and Jazeera and Dubai has some other one I can't remember..................hopping using these is a good idea but they are busy,
Hope this helps?