There's tons of 'em out there but, as you've noticed, most subscribe to the boom & sizzle school of design, which please gamers and which you seem to have outgrown.
for your musical pleasure, you might start thinking about a "real" system which consists of an amp/receiver and a pair of "real" speakers, and perhaps a subwoofer. You can get these in either plain old two-channel, or a full-blown muti-channel AV configuration. You may wind up looking at new sound cards in the process, though.
There are also a few powered speakers but these are not as common and tend to limit your choices.
Likewise, your anticipated financial expenditure has some bearing on what you will end up with as well.
So, what say you?
P.S. I use altecs on my two computers (and a spare system for my ipod) but that's not my main musical source. If it were, I'd be looking at a receiver and speakers.