As some of you may know, I got a Roland MT-32 a while back. This is absolutely great for Sierra games (and some others) up to around 1992, which have music specifically written for the MT-32.
However, after that time, General MIDI became more and more common. Even Sierra wrote many of their soundtracks for General MIDI in their later games (including Space Quest 5 and 6, Police Quest 4, King's Quest 6 and 7, Gabriel Knight, and Leisure Suit Larry 6). The MT-32 is not General MIDI compatible, and although these games still support the MT-32, they just put it in a pseudo-GM mode (they send some sysex commands that reassign patch numbers to sort of match GM). They don't use any of the special sounds or synthesizer capabilities that the MT-32 offers. Although this sounds decent, there are definitely a lot better GM devices out there.
Although good results may be obtained using just about any GM compatible module, the one that many game composers in the mid-90s had in mind when they wrote their music was the Roland Sound Canvas SC-55.
So, in order to further improve my old DOS game sounds I went and got a second-hand SC-88. Why not an SC-55? Simple: I found a cheap SC-88, and it's basically a better version of the SC-55 with some improved waveforms, and more sounds (the latter is not useful for games but who knows if I ever want to use it for anything else). It gives me great quality and authenticity for mid-90s games.
Yes, I'm sure if I'd gotten a more recent MIDI module it would've sounded even better, but that would've been more expensive and not as authentic for the purposes I wanted it for.
I made a video comparing the Sound Blaster to the SC-88 with the King's Quest 6 intro:
The SC-88 version starts at 7:29.
The SB version is actually not that bad, to be honest. Certainly it's not as drab as some of older MT-32 Sierra games. That's because they did a better job on the conversion, and because it's actually using the OPL3 (so you get stereo, for instance) rather than the OPL2 that older games used. Still, the SC-88 is obviously a lot better.
For fairness sake, I should point out that the SB version was emulated by ScummVM, as I don't have an actual Sound Blaster with an actual OPL3 chip. The difference is not that big, however.
As an interesting side note, you might notice that the SC-88 sounds somewhat similar to the Microsoft GS Wavetable SW Synth (which is used by Windows if your sound card doesn't have MIDI support). That's because the SW synth is actually a version of Roland Virtual Sound Canvas, and it uses the same set of sounds as the older SC-55, although at much lower quality.