Emirates are based in Dubai in the UAE, Etihad are based in Abu Dhabi also in the UAE and Qatar airlines are based in Doha in Qatar in the Gulf. In that sense they all share a common area of base.
Emirates are rated as a four star airlines by Skytrax and Qatar is a five star airline.
http://www.airlinequality.com/
All of them are relatively young airlines, they are all highly ranked and they all employ multi national aircrew. All of them take a lot of pride in the languages their crew speak and announce them before take off.
Non of this means much in terms of employment practice though and the only way you will find out is by asking each airline to send you their employment application pack.
I fly Emirates three times a year to Sydney and enjoy their service. Staff always appear well motivated and I love being able to ride in the A380, a fantastic aircraft. Emirates have the largest order book for the A380 of all airlines. I am fairly sure that neither of the others have placed orders.
Qatar Airline is the only one with a five star rating out of the three. there are not many five star ones around. I have only flown them twice but would do so again without hesitation if the situation arose.
I am afraid I have not yet flown Etihad. They claim to be the official airline of the UAE but have had the lowest profile of the three. I look forward to using them in the future.