Ryanair etc
I'm avoiding Ryanair and Air France whenever I can.
I don't like Ryanair's business philosophy and their "passenger = paying cattle" attitude. That's enough to make me run far away from them.
Air France I simply don't trust in terms of safe operation. Too many negative headlines lately which make me believe that there's a serious problem with this airline.
There are many more airlines which I wouldn't trust, but it's a lot less likely that I'll ever have to use one of those.