I live in UAE so I'm a frequent traveller in between the route Dubai to Karachi, frequently travelled with Emirates. I'd say best in aviation industry and best business class suites.
Alternatively travelled with Flydubai as well and once with AirArabia, as budget airlines both are good however I prefer a boeing so I'd go with FlyDubai.
Travelled with Thai Airways, best in class, the 747 is amazing, on-time.
If travelling business class, I always prefer to select Qatar Airways however as it is not available from Dubai anymore, I'd prefer Emirates.
Etihad, is also good but not preferred over Emirates. The seats are not wide enough in business class, prefer the row seating in Emirates more which is 1-2-1.