Sorry. Any airline doing code-share basically has no brand.

MisterNice

I think it depends on where you are.

In my home area, it's Virgin by far. Virtually nobody else advertises at all, but there are tons of billboards, local ads, etc for Virgin.

In New York, CO has ads plastered all over the busses, phone booths, etc. Delta did, not sure if they still have billboards on the sides of buildings. Actually I think Delta is rolling out a new campaign on their changes, it's obviously not that effective because I've seen it, but have to think about who it is.

AA has a very strong branding in their support of many of our events. I don't know if that extends to other not for profits, but they are very strict about how you use their logo, placement, require approval on everything, etc. They don't have the billboards and ads many other airlines do, but are able to reach a ton of people through their sponsorships.

Southwest. That call button thing is ingenious, the way you know it's automatically ANOTHER Southwest commercial.

PanAm does still exist in the US, although much different than the original PanAm, it uses the same logos for branding.

I guess it depends on what you mean by strongest. Personally, I think the fact Ryanair does well despite the constant stream of bad publicity means it has a very strong brand.

PanAm, TWA, Eastern.......where did all the flowers go?

Western Airlines..."The Ooooonly way to fly."

Agreed. Southwest has done a remarkable job with branding.