Had the opportunity to fly MH last year after the MH370 incident; price was *extremely* palatable for a J flight back to AU, but it wasn't my thoughts of safety that helped me make my decision, rather the ineptitude and farcical progress that was (not) being made with that investigation.
The thought of my family going through the exact same thing as those with family and friends on MH370, was what won out in the end. Too much secrecy, too little transparency and a what appears to be a total lack of communication and general failure between all involved at the time of the disappearance, wasn't something I wanted to inflict on my family.
Asiana - flown them once SYD-ICN, but only because it was the only flight available, and Garuda, again only flight available. If I had to fly both routes again, I'd ensure I had input into the carrier selection and give both a miss but unfortunately, often you don't have that choice.
Had to fly AirAsia (Thailand) a few days after the crash in Indonesia, and yes, it was in the back of my mind (I *know* they are two separate franchises); crazily enough I felt much better flying Jet* Asia back to BKK. Safer? No idea, but at the time I felt better knowing I was getting onto Jet* over AirAsia for that return flight.
If I could have flown CX I would have, but I had to fly in early and out later the same day - they don't offer times that suited my schedule. (Jet* was the same - no early enough flight out, but fine for the return journey.)
Would I fly MH in the future? Not sure, the second incident could have happened to any of the other carriers that flew over that area around that time. It's the unknown factor of where MH370 is (and the initial poor response and actions to its disappearance) that is keeping me from choosing them currently; given time, I will probably reassess my take on them, but for now, they are on my no-fly list (which also includes those airlines listed by others above).