I have family over there and over the years we have flown with pretty much everyone bar Virgin.
Our favourites are Emirates and Etihad; long way round, but usually competitively priced, very good in flight entertainment, decent enough seats and reasonable food. For me the big bonus is that the flights are 7 hours to Dubai and 8 hours to Jo'burg, so 3 hours longer in the air than the more direct flights, but get to have some fresh air and a decent walk around mid way. We have had over 20 trips with Emirates in the past 7 years or so and never had a problem.
BA has lost 5 bags on 5 different flights, 3 of which have never been found, the quickest to be returned took 3 days.
Air France staff have been racist to DH in the past, so he now refuses to fly with them.
SAA planes that my extended family have been on have been older planes and the video screens haven't always worked. I haven't flown with them, but the general consensus is that it wasn't a great experience.
A cousin flew with Iberia a few years ago and said it was only ok, but he much preferred Emirates.
Flown once with Lufthansa and they lost a bag, turned up 3 months later.
We have never flown with Virgin as we have found them to be more expensive.