I can vouch for the Shure SRH440s. I've had my pair for 18 months now, and I've found them to be generally pretty great. I have some Neil Young in my library and all I can say is that they sound great with him.
However, I enjoy listening to The Flaming Lips, MGMT, Third Eye Blind, and The xx more with these headphones than Neil Young. I'll admit, though, that I don't really listen to much music similar to him. The phones do sound great with folk(Neutral Milk Hotel), progressive rock(King Crimson, Pink Floyd), and music like Tool.
I just listened to some Sufjan Stevens online, and the phones seemed to perform pretty well, considering it was YouTube. I got a little bored with the music, but I'm sure that's just my musical taste. I could have sworn when I listened to Sufjan Stevens a couple of years ago that his music was much different... Maybe it was a different album -- I'll take a look at his discography and see if anything rings a bell.
But honestly though, the Shures are a really great pair of headphones. Their isolation is absolutely amazing, and can sound very full even at low volumes if you need to hear incoming vehicles. For example, for the past few months I've had a large air conditioner in my bedroom and could "hear" it constantly at low volumes, though even without music playing the cans manage to literally drown out outside noise -- everything sounds like it's underwater. I know the second sentence in this paragraph sounds contradictory, but I can't help it if the headphones contradict themselves, haha. For the record, I don't have a DAC or amp with these headphones. I'm using them on my laptop and iPhone 3GS. I've also used them on an iPod Classic 80GB, and they've been loud and clear with every source.
If you were to get these headphones though, I would probably suggest getting the SRH840 earpads as they apparently help even more with the isolation; and they are supposed to make the cans more comfortable as well. When I first got the headphones, they felt really heavy, slightly bruising the top of my head. But after a week or so, that went away and I was able to enjoy them completely.