Once I get my 486+VLB setup going, I plan to use the simplest, most compatible non-PNP sound blaster I have, which is a CT1600 SBPro 2. I might throw a second card into the mix just to experiment. A PAS16, Logitech Soundman, Yamaha, ESS Audiodrive or CT1740 SB16 (with bug-free DSP) are about as exotic as my cards get. It'd be nice to add something like an Ensoniq Soundscape, but they are hard to find (except for the VIVO... I have one of those and don't want to mess with the TSR).
Honestly though, it seems like most of the features of newer cards would be more suited to something faster than a 486. Unless you're trying to recreate a setup you had at the time, I'd save all the fancy (16bit) cards for a later DOS system with a Pentium MMX or K6. I doubt there were many games that benefited from 16bit audio that didn't also run better on a Pentium.
Time Machine = FIC PA-2013 2.1 - K6-2 500 - 256MB PC-100 - TNT2 Pro 16MB AGP - Labway Yamaha YMF719-E - Midiman MM401