Get Koss KSC35s, and RUN from this place! Don't look back, and your wallet will thank you.
But really, I kid. Welcome to Headfi. Sorry about your wallet.
I'm going to go with my obvious bias and say go for Audio Technicas! A900 or AD900 if you don't mind swinging about 30 USD extra
. With your budget, pretty much anything you choose is going to be well detailed and comfortable. It's more about picking the house sound and presentation that you prefer most. Extra points for Audio Technica: they shine just fine without a dedicated amp in my opinion (meaning you can put all of that into heaphones now, as opposed to having to go with something in the 100-150 USD price point and also budgetting for an amp). Also, AD900 is super comy with its velour pads. Mmm, velour.
Let respective Grado, Senn, AKG, Beyer etc. lovers detail the strong points of their choice cans until you get an idea of the sound you wanna go with.
I'd say my AD900 has a pretty balanced presentation, maybe a little dry. Mids and treble are both forward. Bass is a little reticent, punch shy, but is not lacking in extension or detail. I'm not a professional listener by any means, so just consider mine a user review... I've been kind of thinking about picking up an AKG K240s or K240m to compliment it. Kinda get the reverse of what the AD900 is doing.
I read over the thread again: Discount what I said if you're talking portable. A900 and AD900 are far from portable.
If you have some decent electronics knowledge: Have you heard about the Cmoy mint amps? Do some searches here on headfi and you'll definitely find pictures. Maybe go over to portable audio and check out the 'post pictures of your portable rig' thread, and you'll see a good share of mints. The parts list and instructions are floating around on the internt somewhere. Is it Tangentsoft? Tangent Audio? Another cheap DIY amp that has been getting some attention is something called a T amp. I know nothing about it aside from that...
Sorry I wrote so much.. I hope I was helpful