Gulf Air are just an ongoing disaster, losing a million dollars a day and it shows. Bahrain air are ok for a budget airline.
I have held a Skywards Gold for 12 years now (thanks to the company and a lot of business class travel), and there is no doubt in my mind that their standard of service has deteriorated over the last five years. The long haul flights are still ok, but the regional flights around the GCC are frankly crap, consistently late, and with poorly trained cabin crew. Terminal 3 in Dubai is a disaster, already chronically overloaded, and a high proportion of GCC flights depart from Terminal 1, which involves a sponsored walk from the check in at Terminal 3.
Best airline in this region, Qatar Airways by a country mile.