What airline do you fly normally?

Southwest almost always

It depends on what airline offers the best ticket price but usually I try to go with a Star Alliance airline or SkyTeam Alliance airline.  The last trip I was on, they were all OneWorld Alliance airlines since American had the cheapest ticket to Asia.

Air Saturn is pretty good.  Their choice in movies is pretty far out. Plus the alien cabin attendants are hot.

In the days when I used to fly between south-east Asia and the UK two or three times a year, my favourite was Emirates.

But I have a soft spot for SIngapore Airlines and Lufthansa too.

Mind your own business.

United - I have a ton of Star Alliance frequent flyer miles.

Virgin Australia

I travel to Alaska a few times a year so I usually fly Alaska Airlines however since I live in Texas, anywhere else, I usually fly American. But fortunately, AS and AA just started a new codeshare so ill eventually be able to get AA miles for flying on AA. 

I fly the one that has the most convenient schedule at a reasonable price.

Delta. We have status with them, branded platinum credit cards. and a TON of skymiles piled up.