Sony XB700s are sweet... there is almost nothing they cannot handle and they can do it un-amped in most cases, so straight out of my Sansa, or, if you have a Zune or iPod.
I would say the V700dj phones also from Sony, because, quite honestly, their freq. response is just MADE for dance music. So are the XB700s, as they share the same drivers, but the response curve on the XBs is flat down to well below bass and into low sub-bass. The v700djs aren't like this, they roll off the lowest freq, though it isn't as if they do it at a stupid mark, it's just they are made for dance and DJ music.
On that note, hit a pro music shop and check out some of the less expensive versions of the Sony v6. (not v600). There are a couple Sony monitors that are still over the ear phones that are less expensive than the v6 and sound amazing. Senn HD555s are really good with electronic music, specifically IDM, but a lot of people dislike how they would handle a classical music piece. Your music source, is basically what will drive this. If it is mp3, a good little headamp system, a reciever/integrated with phono plug, whatever, there are headphones that satisft all these technical situations, but may not be for the music you enjoy.
