Any suggestions? $50 max. I used to have (they broke after about 4 years of heavy use) the Sony MDR-CD180, they were pretty acceptable and only cost me $20 on clearance from Fry's but they're discontinued.

The Panasonic HTX7 headphones are great value in my opinion.

A quick search on Amazon.com shows they go from $34.
http://www.amazon.com/Panasonic-RP-HTX7PP-W-Retro-Monitor-Headphones/dp/B000IBRX4M/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1212318207&sr=8-1

Don't be put off by the looks, they are well spec'd on paper IMO and isolation is great for the price-point. I keep a pair in my sound kit as backup to my HD25 because they almost sound as good as the HD25 to my ears (but not quite).

* Encapsulated, Dynamic Type.
* Driver Unit: 40mm.
* Neodymium Magnet.
* Impedance: 40 ohms.
* Sensitivity: 99 dB/mW.
* Power Handling Capacity: 1000mW.
* Frequency Response: 7 - 22,000Hz.
* 1.2m cord with gold-plated stereo straight mini-plug.
* Package included 2 meter Extension Cord, Stereo Standard Plug, and Carrying Pouch.
* Available in 5 different colors, Light Blue, Beige, Green, Black, and White.

I would put another $20 and go for grado SR-60

http://www.amazon.com/Grado-60-SR60/dp/B0006DPMU4

I own the sr-80 but its another $20-30 more.
the sound is very is near amazing, and its very lightweight.
bad side: they don't hide the noise around you, so not for loud place or when to many peoples talk around you.and they feel fragile,and not comfortable after a few hours. but solid wire.

I also have ATH-M30, but they are $9 more than your budget.
http://www.audio-technica.com/cms/headphones/7041339ec2fdcc12/index.html
P.S they are $59 at Amazon
I would recommend audio technica for video production, they are very built solid and the wire also.
isolate sound very good,very good sound quality, and one important thing only one wire one your left hear so you are not stuck in the wire(this is big problem with grado)
So for listenning music in quiet place but have a sonic trip: Grado Sr-80
and for tough jobs in all weather, the audio technica
and audio tech look very pro for video, Grado look audiophile.