Since my Audeze LCD-3 planar magnetic headphones arrived around a year ago, I have not listened to any others (except for brief comparisons and travel.) I have been a fan of the Sennheiser HD580/600/650 line for as long as I can remember, and Audeze just blows them out of the water.
Every time I listen through the LCD-3, I hear new and interesting sounds hidden inside music, no matter how familiar. Listening with the LCD-3 makes my favorite music into a new experience every time.
The cost for this kind of audio quality is not reasonable; you'll do this out of love or not at all. Not only are the headphones expensive, at around $2000, but you'll need a good amplifier and source. I've been using the Schitt Lyr and Bifrost (Beware tube rolling as a new hobby.)
If you get a chance to listen to the Audeze LCD-3s, I don't think you'll be disappointed. Pesco wasn't.