I always come to this board whenever I need to research my next audio investment, though I've never been terribly active. I have picked up a bit of familiarity with what exists in the headphone world, though.
Which brings me to my predicament. At the moment, my rig is just an iBasso D2 Boa amp/DAC fed from my lappy via USB into my Denon AH-D2000s. I listen to a bit of music, but a lot more TV and movies through my computer (sometimes multichannel, but often stereo). This rig has never quite satisfied me. I'm definitely a basshead, and the D2000s are better than my old AKG K242 HDs in that regard, but still don't have much slam, and a lot less soundstage.
I think part of this may be an insufficiently powerful amp (being a portable). I haven't been able to find anything reasonably priced that I'm sure is going to really open up my Denons, though, which is what I want. I'm open to replacing other parts of my rig (separate DAC, new headphones — I've been looking at the Beyerdynamic DT880/990(/770 still produced?), though that may be redundant), as well. Alternatively, would a good IEM solve all my problems (increase bass impact and soundstage)?
Long-term, I'd like to get an Oppo BDP-95 (or whatever version exists by the time I collect the money), build a home theater system (linked to my computer) around it+some amps, and use the ridiculous DAC to feed my headphone amp. Thus, it may make more sense to put money into an amp than a DAC.
My current budget is probably up to $500, ideally $2-300. One other (slightly odd) caveat: I'm living in Japan at the moment (though I can buy in the US and ship, if necessary), but sooner or later I will be moving back to the US, and so really huge/heavy amps are sort of out (in the short-term). I'm also mildly aesthetic-obsessed, so I'm less likely to embrace something really ugly. I apologize for how open-ended this question is, but that's sort of the nature of my problem: what's the next step?