I just got $300 to spend at the Apple store. I think I want headphones, and they sell what have been my Holy Grail, the B&W P5. But I'm going to open this up to anything the Apple store sells in the same price range. Audio source is an iPhone 4, and I have no interest in keeping an amp clipped to my belt when I'm on the go. These have to sound good straight out of a source; I don't have the luxury of owning anything resembling a good stereo - my best stereo component is a vintage SonicImpact T-Amp and THX-certified PC speakers (but their internal headphone amp is noisy!) I'm leaning toward mostly semi-mobile use; they should be comfortable enough to wear for hours, and both small and durable enough to throw in a backpack with a laptop (cases help durability, but hinder portability!). They may be used connected to a desktop PC with or without a USB sound card.
Another relevant point - I prefer an L-shaped plug to a straight one; the Beats low-profile plug is about ideal. I may eventually buy a Beats cable to use on whatever headphone I end up selecting, if that's feasible.
Here is my shortlist to prime the discussion:
Bose QuietComfort 15: Mentioned for completeness, but I already have the ability to borrow the QC3 whenever I need them. The smaller siblings are exceedingly comfortable, but they need an inline mic. I haven't bothered picking up the cable yet. I won't consider these at this price point without a good argument; I don't like the idea of having to keep my headphones charged, they have no passive fallback mode, and there's other good headphones at this price point that probably sound better.
Parrot Zik: I like what they're doing and respect their ambition. I have no idea how they sound or feel, and they're $100 too expensive, but they deserve an honorable mention for engineering merit; the NFC pairing is a breath of fresh air, the Jawbone-made, dual-transducer and dual mic transmit side is … I expect very good things from it, and the logic of "If a call comes in and you take off your headphones, send the call to the phone" seems blatantly obvious only in hindsight. I'd get these if I could afford to throw an extra hundred into the pot:
http://store.apple.com/us/product/H9557ZM/A/parrot-zik-wireless-headphones-by-starck?fnode=3d&p=2
Incase Sonic: I own one. This is my baseline, my "reference" can - I like them a little better than the HD 280 Pro, mostly because I can wear these for a few hours without pain. When I listened to a lot of Iron Maiden in short sittings, the 280s were perfect however, but the Sonic sounds better with more kinds of music. They don't fold, but they have a Red Dot design award, they're light, comfortable, light, and adjust in all the same ways as the 280 with a much smaller mechanism. They're also less hot than the Sennheisers ever were.
V-Moda Crossfade: If the Apple store sold these, I'd probably not have posted here today. I find the clamping pressure a little low, but I can't criticize the sound in any way, shape, or form. A friend of mine scored a pair for $50, and I'm still pea-green with envy.