I've only just read the first post of this thread today, but haven't read all 74 pages!
Out of MacedonianHero's list I have the PSB M4U2 and the Bose QC15.
The Bose QC15 is what I use when travelling, as they really do have superb comfort and isolation. I have 2 gripes about this headphone:
1) The QC15s are supposed to have an integrated amplifier, but it must be tiny because driven by smart phones like the Samsung Galaxy S and Note lines, if you have rooted and modified the system files to boost the volume, then they have enough power to drive these headphones, but most people using those smartphones in the stock configuration wouldn't bother with all that. For that's your main source on a plane look at the PSB M4U2's instead. (The Nexus 7 is another example of a source with a low volume output)
The HTC One on the other hand drives the QC15s just fine.
2) Related to number 1, the QC15s really need an equalizer in my opinion to get the best out of them. Unfortunately, especially if you like bass, this limits the volume even further.
I like the QC15s, they are incredibly comfortable, but if your headphone jack output is a bit lacking, you will need a separate amp. The carrying case for the QC15 is fantastic and they have great battery life as well.
The PSB M4U2 is another great headphone, and as it has a (decent) inbuilt amplifier, i haven't been able to find a source that can't give you ample volume. These are great but I have 2 main problems with them:
1) The headphone itself feels quite heavy and as someone with a large head + wears glasses, these can get uncomfortable after long listening sessions too.
2) The carrying case is massive and the headphones don't sit in there as nicely as what i'd like. This detracts from their portability a bit (so much that i've never actually used the carrying case)
The included accessories are great, except they forgot one tiny thing - a replacement battery cover. I have tried contacting the company directly and they put me on to a reseller in Australia to get a battery cover replacement, but I haven't been able to get one as yet.
You'd think that someone in Asia could make one for about $1 but apparently not.
The batteries hold firm in side the headphone anyway, but I don't like hot sun against them in summer (makes the batteries warm up quite a bit) and it just looks wrong - i feel self conscious about these headphones when i'm walking down the street with no battery cover on the side. I'd use these headphones a lot more often if i could find a replacement cover (or the original for that matter). For that reason (no battery cover) I would probably never use these on a plane.
Instead next time i fly i'll give the Fiio E12 a try with them, if I haven't purchased the JDS Labs C5 before then. (I decided the iBasso T5 is completely useless with the QC15 on my last trip away)