Best pair of Headphones for under $150?

Are you looking for open or closed headphones?

Are they going to be used for music, gaming, movies, or other?

What source(s) are you going to be plugging your headphones into?

if you are going for closed I would say Audio Technica's ATH-M50, very crisp and clean sound with a wide range of music genres. If you are going for an open headphone, I would recommend grado's sr80. They have a very unique detailed sound that you either love or hate. Their disadvantage is comfort, which is big for some people. I personally do not find them that uncomfortable and love their sound. Hope this helps!

I just recently got the Shure SRH440's and I love them. 

http://www.amazon.com/Shure-SRH440-Professional-Studio-Headphones/dp/B002DP1FTU/ref=sr_1_1?s=electronics&ie=UTF8&qid=1320718725&sr=1-1

.... and wait for the influx of fostex t50rp votes

M

SR60 is a very good value, especially without an amp. I found the SR80 to sound almost identical to the SR60 unamped, but even with an amp, the differences were subtle.

SR80 is an amazing set of cans for the price.  They are also easy to mod in case you get the itch to do so in the future.  I would say the SR80 over the SR60 just because an amp will do very little for the SR60, but I think it can really make the SR80 shine.  So the SR80 is easy to upgrade or change to suit your needs (as long as being a closed can is not among those needs).  I had no intentions of modding my pair when I bought them, but since then they have been woodied (cocobolo cups), reverse quarter-modded, and vented, and they sound just dynamite.  And, if they aren't your thing, they retain their value as well as or better than any can out there; just sell 'em back to any lucky hi-fier and at least you'll know Grados just aren't your thing.  

I haven't heard them, but you could easily find the SR125s for under $150 if you're lucky or willing to go with used.  Again, I haven't heard them, but being the step up from the SR80s I can only guess they are better. 

Good luck finding your cans!

SRH840, Ultrasone HFI-580, Fostex T50RP (if you're into modding).

Shure srh840 or Shure srh750dj

The srh750dj for if you want bass and the srh840 if you want neutrality.