My workplace has become absolutely impossible without headphones, so I recently went on a search for something better than what I had on hand, and ended up with three pairs. Specifically I wanted closed 'phones so that I don't drive my coworkers as insane as they drive me, but I didn't want noise cancellation.
* Shure SRH-640. Amazing sound, but a bit heavy and annoyingly prone to creak every time I move my head a millimeter. I keep these at home for light use.
* Beyerdynamic DT-235. By far the tinniest sound of the three, light and comfortable for short period, but boy do they make my ears feel hot after a while. I might start taking them on planes; otherwise I don't use them.
* KRK KNS-8400. A noticeable step below the Shures in quality, but still better e.g. than the HD-280 which I've also tried. No creaking and comfortable even for long-term wear. These are my every-day phones at work, even though the extra-wide headband does look kind of goofy.
I'm no audiophile by any stretch of the imagination, but even I can tell that some of the popular brands are absolute crap. It's too bad more people haven't heard of brands like Beyerdynamic and KRK, because they actually do make much better-sounding 'phones at prices that any geek should consider quite reasonable.
For a real geeky good time, go to http://www.headphone.com (no relationship except that I bought the Beyerdynamic and KRK from them) to check out the frequency response curves and such.