Good Headphones Around or Under $300

[28BlusLater]

I have never had a really nice pair of headphones. However, I'm getting sick of wearing the crappy Apple headphones that continue to easily break and I have to keep getting them replaced under the warranty for my iPhone. Not to mention that they aren't comfortable and the audio quality sucks.

I will be getting a new pair of headphones soon, but need some help on what headphones to get. I don't want any in-ear headphones. I'm looking for over-the-ear headphones. I have been researching for a while, but cannot seem to find a few to compare. I'm going to demo some headphones this weekend at a few stores and would like some suggestions of headphones to listen to.

So far, the only pair of headphones I have found I'm interested in is the Sennheiser PXC 450. I would like to get some headphones that will last a long time, sound great, and are comfortable. Are noise cancelling headphones worth it (I know the PXC 450 is NC) or are just normal over-the-ear headphones fine?

I would primarily be using these headphones at home on my computer while doing some work. I don't travel much, so I won't really be on many planes with these.

Also, just to clarify, they have to be around or under $300. What's the best I can get for that price range that fits what I'm looking for?