D1100 vs HFI-580/680/780

I've been looking for a closed set of headphones for a while now(for both gaming & enthusiast audio), and through the kind people at head-fi, I've narrowed it down to 2 models (3 variations of one model).

I've been a long reader of overclock.net, very knowledgable people with everything revolving gaming entertainment, so I thought to make an account today and ask your opinions on a few headphones.

HFI- / /
Beyerdynamic DT660

Intended uses:
Gaming
Electronic Music
Orchestrated Music

Priorities:

Quality - I would like my friends to get that "wow" factor when they try on the headphones, so I can prove to them that it's most definitely worth it . I'm not necessarily looking for the unnoticeable (to the untrained) marginal differences as most audiophiles do (such as differences between the HD600 and HD650), but at the same time I am still looking for the best quality I can get for my price range.
Isolation - I would've put official noise-cancelling headphones in the list, but i really don't want to have to maintain a battery in my headphones
Comfort - As a gamer/student, I'll be wearing these for a couple hours at a time
Bass - Bass isn't super important, but I would like it to have that nice punch.
Highs/Mids - Clarity, important to all audiophiles. (Even though I don't consider myself one)
Soundstage - I don't usually play FPS games(I'm more RPG/RTS), but I am looking for the best soundstage I can get out of closed headphones.
Amp-less - I would like to not be required to use an amp to get the quality of my headphones, as I would mainly use it for my MP3 player/laptop computer.

I originally heard fantastic review from this and this thread of the Denon D1100's, but before I purchased them I was informed of the HFI's; Also found some Beyer DT660's for a good price, unsure if they can be driven amp-less.

My price range is really under $150, but if the higher end Ultrasone's are really worth it, then I'll spend a bit more.

I'd really appreciate the help

UPDATE: This is an old thread, after experiencing some headphones my budget has been raised and options increased.
Edited by Scytus - 4/5/11 at 12:55am

bump, updated

I tried out the HFI-580 and the PRO550. The PRO500's seemed anemic in bass, and the 580's were decent, but lacked a bit in soundstage.

I'm going to a headphone meet in the 21st of this month and hopefully there I'll be able to give the Pro900's a try with a Matrix M-Stage amp, as that seems the good choice for me.

Its almost the most difficult task, to find a Hi-Fi sound with a large bass presence, and a wide soundstage.

Oh yes, I tried the previously mentioned with a Little Dot DAC_II. I gave the HFI-580 ample time for burn-in, and they did sound noticeably better after doing so.

To be honest however in regards to the Pro550's, I did not give them enough time to completely burn-in, though I should have.

I also tried some LCD-2's, ED9, HD600/650, the (newer) DT770's and the Beyerdynamic T1 at an audio store when I visited my parents in LA. The LCD-2's were disappointing, from all I've read about them, they were actually quite dull. The ED9 was nothing special, small sound-stage. The HD600/650 were very murky, I didn't like them at all. The DT770's had surprisingly non-existent bass for closed headphones. Lastly the T1 did an excellent job in everything, and I really started liking them, but they were unfortunately bass-less themselves.

No problem! i think I'm striving for the same sound signature you are, I'll keep you updated on my thoughts when I head to the audio meet later this month.

Oh also let me know what you think of the Pro550's, I've been regretting not giving them enough time to burn in. That, and now I remember that I didn't even drive them through an amp. I was however upset with their sound leaking, for closed headphones it was surprising.