I have a small collection of oldish sound cards. The collection includes:
Sound Blaster 2.0
Sound Blaster Pro 2
Sound Blaster AWE32 (CT2760)
Sound Blaster AWE32 ISA (CT3900)
Sound Blaster AWE32 PnP (CT3990)
Sound Blaster AWE64 Value (CT4500)
Sound Blaster PCI Audio (x3) (some might have been sold as PCI128 etc.)
Gravis Ultrasound Extreme
Gravis Ultrasound PnP
Roland LAPC-I
Roland MCB-1 (Midi Breakout Box for LAPC)
The ones I have in active use are:
Sound Blaster AWE32 ISA (CT3900)
-This I use in my main Retro-PC. Good for general Sound Blaster -support and takes 30-pin SIMM:s for loading tracker music samples and SoundFonts. I have installed 8 megs of DRAM on this. Better sound quality than in CT2760 but without the PnP-problems of CT3990.
Sound Blaster PCI Audio
-I wonder where all these come from? In every "trash-PC" I've ever received there must have been one of these inside. I know that I have given at least one or two of these away and still they crawl out of my drawers (the "x3" might be an underestimation). Anyway, they should work in DOS without problems, but require some drivers to be loaded. I use one in my secondary Retro-PC, since there is only one ISA-slot present and it's taken by GUS PnP.
Gravis Ultrasound Extreme
-This I also use in my main Retro-PC. Good for Ultrasound-support. Has full 1 meg of memory, which combined with GF1-chip equals GUS-MAX. Additional to GUS-MAX there's ES1688 on board for Sound Blaster Pro -support, but I havent' yet succesfully used it (haven't had time to experiment, since I use the AWE32 for SB Pro (yes, without real stereo)).
Gravis Ultrasound PnP
-Combines Ultrasound-support with better sound quality and 2x30-pin SIMM slots. I use this in my secondary Retro-PC for Ultrasound-support. I have installed 2 megs of DRAM for gaining support for Ultrasound "Classic". 1 meg would be enough, but I have plenty of 1 meg SIMM:s lying around and there are two slots... The reason I don't use this in my primary Retro-PC instead of the GUS Extreme is, that I think you cannot make something "sound better" without altering it somehow. The GUS classic it was when the demo-makers made their demos etc. so "most classic" hardware it shall be in my main Retro-PC...
Roland LAPC-I
-This is it: the perfect sound card. Does only one thing but does it with style. Only midi-support with additional midi-instrument sound effects compared to Roland MT-32. All the old classic adventure games from my childhood sound very nice with this one. If some games that support this needs also Sound Blaster for digitized effects, I have one in the same system. Anyway the music sounds better using this card in the games that would also support AWE32 wavetable, so figure that out. The ROM is only 1 megs, but the hardware is used for everything but the very first milliseconds attack-period. I think the card can be also used as a pure synthesizer without the PCM attack, but haven't tried (I will be getting a midi controller for christmas and start experimenting...)
Time for summary:
I couldn't live with only one sound card, especially when trying to have old hardware for old games and software... Also the question "which is the best sound card" is absurd when it comes to old cards.
With new cards when software synthesizes the sounds, and the number of channels needed go according to the used loud-speaker configuration, the best sound card is the one offering the lowest signal-to-noise -ratio and highest dynamic range with flat frequency response. Of course assumpting that all the needed features (number/type of connections etc.) are present...
Earlier, before standardized software interfaces, this wasn't enough; the support offered in software was essential and the fact whether the card was the one the composers used or not, or did they only convert their stuff to it (usually hastily). The support for Roland LA-synthesis (MT-32, CM-32L, LAPC-I), Sound Blaster digitized sound / FM-synthesis, and Gravis Ultrasound are essential for me when talking about "what is absolutely needed" in retro-gaming or watching old demos. Others usually mimiced these (SB vs. PAS) or were technically poorer (LAPC vs. IMFC).