At the moment, I'm keen on being able to properly simulate a room full of speakers in a 7.1 array. It really helps with video games and movies in particular, as the directionality is something
that no headphone can convey no matter how large a soundstage or brilliant the imaging is. There is no replacement for actual audio information placed properly in a 360 degree horizontal circle around your listening position. So if you want to hear something being truly behind you, you need virtual surround on ytour headphones.
I'd take a $15 KSC75 with virtual surround over an HD800 in stereo for my gaming purposes. That's how important virtual surround is in object placement location.
I have a few that I think really showcase the strength of virtual surround based DSPs.
1.
Redscape Audio - This one is my current fave. You can also get it with a headtracking dongle, which if you've heard the AUdeze Mobius with Waves NX headtracking, it's similar to that, but for any headphone.
2. Creative's SXFI - This is one of Credative's newer surround implementations, and I actually think is the mosty convincing, but it's also quite processed sounding, so it may turn off a lot of people unless (as we discussed) you allow your ears to adapt to the change. SXFI is available on many devices that Creative makes, though not sure on software based solutions.
3. Waves NX - Particularly on the Audeze Mobius, it's really quite immersive and gives you an easy all in one solution with headtracking.
4.
Darin Fong's Out Of Your Head - This one is quite pricey, but you get a bunch of different real life venues, studios, home setups recorded and simulated on your headphones. It's quite brilliant, as you get to hear what they sound like on your headphones. Again, it's pricey.
5. Creative SBX - Creative's other surround implementation, I feel this is the best for people first getting used to virtual surround, as it is the least processed. It still does a fine job emulating surround properly, without it sounding too processed. This is the first choice I'd give any newcomer. It's found on some Creative hardware like the Creative X7, and G6. The great thing is that you can send that surround emulation digitally through optical out to another, better DAC if you wanted. Or just use these as a DAC to a better amplifier.
6. Sennheiser GSX - This is one of the best, but it's tied to some Sennheiser hardware that I feel limit its potential.
I should add that Xbox now utilizes Dolby Atmos at the hardware level, and Sony Playstation 5 uses Tempest 3D audio, both which when properly utilized, are great alternatives to the above.