mini-rant:
Game developers have given sound design short shrift far, far too often IMO. In total I've found very few games that actually have gotten it right. Even with the Xbox's 5.1 Dolby Digital capability, it often falls short IMO. Sound quality is probably my #1 complaint.
Often, weapons or cars aren't gutteral enough. That is, they don't have a visceral or real quality to them. It really sounds like many games use over-compressed samples for their in-game stuff. I'm not familiar with what encoding techniques or what bit rates most games use though so take that FWIW. Not unlike the video portion, I'm sure that developers have hardware limitations in this regard as well though, so...
rant off/
That said, in my experience, two of the better games are PGR2 and Doom 3. Halo is pretty good overall as well. The neat thing about PGR2 is that the sound varies as you go over different road surfaces. This effect registers in my surround channels. If you're way ahead of some cars and pass under an overpass as they're crossing it, you can hear them over head in the surround channels.
Doom 3 has pretty good sound overall- at least the surround mix. Your rear channels will get somewhat of a workout with it. Again though, the sound quality of this game could be much better IMO. The PC version's sound quality is better, but of course it doesn't have 5.1 DD, so it falls on that point.
Two of the more stand-out sound implementations I've heard on the PC are Call of Duty and AVP2. That bit on the bridge with the Brit paratroopers in COD is quite impressive with all the bullets ricocheting and shit it's pretty overwhelming. With AVP2, they really nailed the sound and feel of the weapons found in the movies very well IMO.
BTW, one Xbox game I forgot was Ghost Recon 2. It has a fairly solid sound presentation.
Anyway, JMO.
EDIT:
I wasn't sure if you were asking for reference standard type sound presentations or just games with surround tests per se.
