1. Audio Technica ATH-AD2000
Very forward sounding mids, but not too much. Vocals sound amazing on these, especially female vocals. The sound out of these is very smooth and there is not too much of any one frequency to my ears despite the forward sounding mids. I prefer these to the K702 I had a week ago. I felt the detail was higher on these, but the sound on these feels a tad less clear, but most will probably not notice. It's so nice having a headphone that sounds better than a K702 and not having to be tied down to an amp 100% of the time. These would be good as a headphone that's good for everything. It's also perhaps one of the best gaming headphones there is. Comfort is not that good and terrible with some heads. I had to do a easy and cheap mod. Now my ears don't sit against the driver. This problem is why I'm not raving about these things. I also feel like the pads are massive on my ears. I paid $425 for these like new and I thought they would be only slightly better than a $300 headphone. Boy was I wrong! I still would never pay over $500 for a pair. OK, maybe $550, but I don't know if they're THAT good. BTW I wonder what fans of the ATH-AD2000 upgraded to? Seems like it's always the LCD-2!
2. Sennheiser HD-598
I bought this only because I heard it had some forward sounding mids, which is what I love in a headphone. I wasn't expecting to love these and was pretty sure I may end up returning them. It turns out I loved them so much on the first day that I just had to keep them. I even have to admit that I now even prefer these by far to my old HD-600! The sound isn't as laid-back as most Sennheisers and these sound good for vocal oriented music and most pop. I listen to a lot of Jpop on these and they sound really good with that. These do have lots of detail, but they're still very forgiving of lower quality recordings. These definitely couldn't pick up any sort of recording hiss, but that's a plus for me. These actually feel a lot brighter than the HD-600 and HD-555, which is what I prefer. Music is just so fun to listen to on these. If I had to keep only one headphone I could probably go with just these. Even over the ATH-AD2000. These aren't that much worse to me. The AD2000 is much more clear though, has a bitter soundstage, more forward mids and more detail. The HD-598 is more comfortable though.
Main reason I love these is that they're great for gaming and movies. I actually find that these are on my head more than the ATH-AD2000, but they're not better. I thought the ATH-AD2000's sound was pretty smooth, but this is even more so. My only complaint with this headphone is that I hate the color. That's it. BTW the soundstage is quite impressive on this compared to the HD-555. Felt it was worth the $170 I paid. If I had known how good it sounded, I would have paid full price maybe.
BTW I loved the K601, but it had a few issues that forced me to sell them. These seem to fix the problems I had with the K601 and I prefer these over the K601 and even the K702! The sound of the K702 is more clear and more detailed, but the mids are a bit more distant sounding (not recessed) to me. The sound from these just make my music sound more engaging, which I am perfectly OK with.
3. Koss Pro DJ 100
Basically this is just about tied with the HD-598 in terms of sound quality, but the HD-598 gets more points because of better comfort and a better soundstage. I love how these are so cheap ($80) and sound so good. It's too bad these haven't caught on much. They deserve to be up there with the Porta Pro and KSC75. The mids are what I love the most about these. They're slightly forward, but not as much as the ATH-AD2000, but close. I've found that the level of detail is very high. The sound feels crystal clear to me and that's surprising for a $80 headphone. Imaging is good and I think these would make a good closed gaming headphone on a budget. Obviously an open headpone is best. The only negative is that these aren't exactly easy to drive. A Sansa View isn't enough to drive them, but an Ipod Touch makes them sound "acceptable". To drive them to their full potential, something like the Nuforce Mobile or Total Airhead is best. BTW the bass on these is very good and just below bass heavy. Despite the extra bass, the sound is very well balanced. Even with my other headphones, I still use these everyday and have been raving about them since I got them. They do have very slightly rolled off highs, but it's not a big deal for me. An open version of something like this from Koss would be amazing I bet.
4. KRK KNS-8400
One of the most comfortable portable headphones there is. It's most definitely a studio monitor and doesn't try to make my music sound better than it really is. There is also not a lot of bass on them. They do need a ton of burn in or else the treble will stab you in the ears. These are probably the most detailed headphone I' own. As a studio monitor I'd take these over the K240 Studio or Shure SRH-840 anyday. Soundstage is not that good unfortunately. If there was an open version of something like this, it'd be one impressive gaming headphone. BTW I liked these so much that I bought my old favorite the SRH-840 again to compare them. I ended up thinking the DJ100 and the KNS-8400 were better headphones.
5. AKG K240 Sextett
To my ears these are only about 10-15% better than my K240 Studio. I'm not really impressed with them. They do have good mids, but I don't think they're forward sounding in anyway, but I wasn't expecting that. Soundstage is OK. Level of detail seems a lot higher than the K240 Studio. Level of clarity seems just very slightly better than the K240 Studio. Don't hate me, but my DJ100 sounds very similar and a lot better to my ears. They do have more bass though. I do like these headphones. Who would have known a headphone that was once $80 could sound so good? If you've got the amp for them, I'd take these over the K240 Studio. BTW I feel that these don't make music any more fun to listen to despite what some people say. I find them quite neutral overall, which is what I kind of expected. Like my KRK they don't try and change my music in any way.
5.1. AKG K240 Studio
When I had my favorite DJ100 out on loan, I used these and loved them. When I got my DJ100 back, the K240 Studio never got used again much. They're still very good and even a good HD-555 alternative for gaming. I actually prefer these to te SRH-840 due to the comfort. I sold my M50's and ended up with these and then the DJ100.
6. AKG K44
I posted a link to a deal for this back during Christmas and was telling everyone how great they were for the sale price of $30. Stupid me took that back when I found out I had the bass reduced!! Opps! Without an EQ I don't like these. These have terribly bloated (and bad) bass, but when you EQ it down the sound is very, very good for a $30 headphone. Sure, they're ugly, but they're quite comfortable. For a $30 headphone the sound is very clear and they have very good mids. One of the few $30 headphones that isn't garbage.
7. Beyer Dynamic DT-235
This is with the DHP-II pads. Would you believe that these headphones with those pads have too much bass?! I have to EQ it down a bit. I almost never use an EQ! When I do this they sound "good", but they don't impress me. The level of clarity is much worse than the K44. K44 has much better mids and a far bigger soundstage. With the DHP-II pads they're the most comfortable headphones I've ever owned.
8. Koss UR-55
These have dropped down a few ranks ONLY because of the comfort. I hate the pads and wish they were more circumaural. Without removing the grill, the sound is just "good". When you remove it, it helps the sound out a lot, but you lose out on some bass. When modded, you can even hear recording hiss with ease on these! The sound on these is not crystal clear and very, very slightly muffled. It's like a modded SR-80 with more detail, more bass, more rolled off highs, but less clarity. It even has a better soundstage! I think these could make a decent dirt cheap gaming headphone! Fans of the Porta Pro should love this headphone.
9. Sennheiser HD-497
I use these in my bedroom as a TV headphone. I hate them and I think I originally paid $70 for them when they first came out. I can't remember. I've had them for probably five or six years I think. To me they sound worse than the DT-235. I actually hate the bass on these. I don't know why, but all my cheap headphones have too much bass.
???: Modded Grado SR-80
I think these have good mids, but I don't think they're all that detailed. I compared the level of detail on them to the modded UR-55 and DT-235 and they lost out. Unfortunately I can't wear these AT ALL.I've tried and tried without any luck. Sorry! Soundstage and imaging seems poor too for some reason. I think this is the headphone I've owned for the longest period of time.