Best closed can (and among best cans ever) I've yet heard (and owned) is the Kenwood KH-K1000. There's nothing I dislike there. Great low end response and extension, perfectly integrated and well balanced mids (somewhat mid forward even), extended but not harsh/sibilant treble, great soundstage, decent isolation, super comfy, fast, and musical. What more can you ask for? Oh, and just to ice the cake - they are probably one of the least picky cans out there in terms of amp/source matching. None of the "hard to drive" Beyer issues or "noise sensitive" Denon concerns.
A close second would be the Denon D2000 - they're far more sensitive, which means if you have noisy components they might be a bother. They don't isolate as well either, but the sound is nearly as good and they're easier to track down and cost less. Sound-staging and positioning is great, but the "they might as well be open" jokes aren't far from the truth; the Kenwood does all that with isolation and no harshness.
Not even fair against other cans (various Ultrasone, T70, etc). Denon are better, Kenwood are much better.
I'm myself curious how they compare with the AT W1000X (Grandioso) and W1000 (Sovereign) - they're often regarded as being "smoother" and "brighter" than the Denon models, but I see "sibilant" and "picky" in a lot of reviews too. The one review I've found of the K1000 (with measurements) compared it to the W1000 favorably, fwiw. Never read about it against the X. Can't source Sovereign anymore, and X is fairly expensive just to satisfy curiosity.
There's also a few closed-back 'stats out there, like the Koss ESP/10 and STAX 4070. I've had the Koss, and they're good (they're HEAVY though) - the STAX are supposed to be world-beaters. If you can deal with minor leakage, I'd throw the current Koss 'stats and Sennheiser 580/600/650 onto the list as well. Less bass than the Denon or Kenwood, and Sennheisers will pull the mids back a little bit (it's not bad except for movies - the ESP/10s are sort-of dark too). Still good sound-staging/imaging, musical, not fatiguing, not harsh, etc. You have more robust amplification requirements for the Senns relative to Kenwood and especially Denon (300 ohms and it's neither as flat nor as sensitive), and the Koss come with their own amp (which is competent).
Get the D2000 or the K1000 and a competent little amplifier and be finished with it is what I'd do. If you're worried about heat, get an HD 600 (velour pads, open-back, etc). Same money either way (Denons will save you $100 though, but you could get the D5000 if you want the wood look - they should be around $400-$450 while they go out; take care with the lettering). The current Koss ESPs might end up at parity with an HD 600, D5000, or K1000 (they're all right around $400) + amp ($200-$250 on an amp isn't that absurd), so at least think about it. D2000 + amp (say like an E9 or EF2) could probably be done inside of the price envelope of any of those three though ($300 cans + $100 amp) - that's a value right there.
