This is a topic that comes up frequently, and is kind of dynamic. Furthermore, whenever many/most of us have bad experiences, we tend to write off the airline(s) that provided them.

Anyway, my current list remains:

MU
CA
FM
CZ
HU

I recently moved MU to the top spot because I really like their service in F and C. I simultaneously downgraded CA because, while they are operationally sound, I think their employees are kind of lazy/rude.

However, today I had dinner with a guy that is a truly an expert in this area (he brokered SQ's MU share purchase, is currently working on selling Oasis's assets, and has been involved in scores of other similar transactions; more impressively, none of his deals have ever resulted in a bankruptcy).

So, I take his opinion seriously. But, interestingly his list is very different from mine (keeping in mind that his criteria are not the same). His list:

HU
CZ
CA
FM
MU

(almost the opposite)

He told me a lot about HU that I didn't know, including some impressive details about its PEK-SEA flight. We simply had to disagree about CZ and MU. His main point was that CZ makes money while MU loses it (and is too cheap to bring in a management team capable of changing that situation). I guess I don't care about the bottom line as long as I'm a passenger and not an investor.