This is a very tricky area. I just did the same research so I will offer my help, but this is a very personal decision.
-- Closed cans that contain their sound well.
-- Closed cans that isolate you from outside sounds OK, but the nth degree of isolation was not crucial for me (as I just turn up the volume). [Note that containment and isolation are not the same thing, and some closed phones do only one of these well, like Denon D1000/1001's, which contain but don't isolate].
-- Sound good with my Predator and/or iQube amp, but also OK without an amp. I use a Cowon i7 and a generation 5.5 video iPod (actually an iMod). And an old Sansa now and then.
-- Are not so expensive that I am totally heartbroken when they get stolen (hey, I live in New Jersey).
-- Do not look geeky or strange. No big cans, no bowls, no wood. But at the same time look up-scale and say "I know headphones and you don't" (yea, I'm shallow).
-- Traditional over-the-head headband (not behind the neck -- that's where the gym towel goes), and traditional sit-on-the-ear pads ... cover most of the ear, but not surround it (i.e. supra-aural, not circumaural).
-- Fold up in some way. Good enough for me if the pads swivel so the phones become totally flat (and slip in next to my laptop in the briefcase). Other people will want true folding like a pretzel or a snowball -- lots of phones do that, but I just need flat).
After searching and reading, I chose Audio Technica ATH-ES7
:Amazon.com: Closed-Back Portable Headphones: Electronics
Actually I chose the black headband, not the white, but the link I gave has the best photo. Some sites say the list price is $285, others say $170, but it's all BS. I paid $115 -- that's the price from the link above.
Some of the photos on some of the web web sites make the backs look bowl-like a bit. They are not. They are very slim and dead flat and highly polished -- really sharp! And look-wise I need all the help I can get with the older ladies at the gym (check out my photo and you will see what I mean. Actually the only lady I try to impress at the gym is my wife, but that's important too, no?).
The SQ is excellent. I am very impressed and happy. But I'm older and the hearing is not as sharp as my college days. You should listen. I think they are carried at Apple stores, so you should be able to try them. If not, be sure you have return privs wherever you buy from -- the headphone game is about listening first, so audition for sure.
If you don't mind traditional (small) bowl-like phones, and you don't want real isolation, the Denon D1001's
are amazing and being deeply discounted now. SQ (for my ears, anyway) approaching the best of all dynamic closed phones (I have listened to lots), and not too big. Boring looks.