If you ask most mainstream people about the benefits of a home theater setup, they would probably mention the crystal clear clarity of action movie explosions and car crashes (which I'm not particularly interested in), the silky smooth and witty banter of sports commentators (which I'm not interested in at all), or even just the in-ya-face gunfire from your standard brown/grey first person shooter (see previous parenthesis).

However I'm posting here instead of there because I (and I assume other people here) am instead more interested in video game music.

What brought this issue up for me was that several years ago, I listened to Shadow Hearts' (PS2 RPG) soundtrack. Not too long after, I played the game. There is a track on the first disc called "China ogre" and that serves as the boss theme for that part of the game. I don't know whether it was because of my sound system or because of the sound data of the game itself, but I was disappointed to hear that the voice/synthesized voice during the song was more muted/soft than usual, compared to the one on the original soundtrack, which was a lot clearer (the voice) on my standard 2.1 speakers.

Music quality is important to me; that is one reason I will only play GBA (and its predecessors) and PSP games on a proper television, not a tiny (compared to TV) screen with a tiny speaker(s).

Hopefully a proper sound system can solve that.

So with the equation in the topic in mind, what should I be looking for when it comes to enjoying the music in my games? Is it simply a case of "buy the most expensive one"? Or might there be certain nuances between sound systems? For example, one sound system might be "optimised" for sound effects like explosions, while another might be more suitable for ambience or whatever. Similar to how plasma TVs (used to?) be more suitable for fast moving pictures like sports than LCD screens (which has or had screen/motion blurring). I'm a HT noob so I just made that up as an example.

Do you own a HT system with more than 2 speakers and at least 1 sub-woofer? Did it improve your RPG aural experience? How about the sound quality for retro games (i.e. using top-of-the-range speakers for 20 year old SNES/SFC games)?

I'd recommend checking out www.audioholics.com.  They tend to have a large home theater base that should be able to address any questions you may have.

For the record, I have my TV and video games hooked up to a pretty nice set of gear, and it does improve the experience considerably.  The sound is just so much clearer through my speakers than it ever was through the TV, and there is a lot of additional nuance that you pick up on.  My CD listening happens on another system, though, which is pure audio.

If I were to start over again, and I was looking for a new system with a respectable budget, I would look hard at active speakers, which combine the speakers with the amps.  Another solution I have heard nothing but effusive praise for is the Linkwitz Orion system:

http://www.linkwitzlab.com/

You can build them yourself (at significant savings), or have them built for you.