Keep in mind by PSG, I specifically mean the PCE or the SCC (konami) chip ones, I don't mean the NES or SMS. Those two PSGs are in a league of their own especially since they're at a slight disadvantage when you compare them to the PCE/SCC PSG.
RTYPE FM
RTYPE PSG
Some NES and SMS games sound as good as or better than 16-bit console games at times.
Emulation isn't very good for comparing PCE PSG sound, especially games like R-Type.
As far as PSG vs FM, hard to say. Both can be used wrongly, but FM done wrong sounds much worse than PSG done wrong. I think it takes more skill and talent to make FM sound right, but since PSG has such a narrow range of sounds, almost anyone can make it sound fine. Pretty much the only thing that differentiates most PSG tracks is the actual composition. When they are both done right, they are both awesome, but I think I prefer FM done right as it has much more bass and seems to have a much broader spectrum of sounds as well as frequency response. However all FM versions of R-Type I have heard simply doesn't even compare to the PCE version!
There is a good variety of PCE PSG sounds, even if there isn't nearly as much variety of
games using different types of sounds. From what I've heard about PCE development, I think that it was a lack of skill and talent (and/or tools) that limited PCE PSG from having more variety more often.
I have a hard time with the music in Air Zonk. I think it is mainly because of the ultra-scratchy drums and other scratchy digitized sounds used in the music. The composition of the music itself is good in some stages, but it is no masterpiece.
Jackie Chan's Action Kung-Fu (and boy oh boy is it ever action packed!) has some fantastic PSG.
Although I love Air Zonk's music, I still cannot get into Jackie Chan's. I'm hoping that once I have the time to play through the game again that it'll sink in, but after trying so many times, I can't listen to the tracks for very long before skipping on to other ones and then to another game altogether. I had the same problem with Legendary Axe II for years, but finally came to appreciate it. Not coincidentally, both are games I only played through as rentals back in the day.
PCE PSG is my favorite of pre-sample based sound. I love all pre-SNES system generated sound and then the SNES/GBA to a lesser extent. I don't really look at it as a matter of which is better, for me it's all just
different. I still have preferences with cross-platform games, Ys III probably sounds best on Famicom other than the PCE CD music (at times it even surpasses
it). The Fantasy Zone music hidden in Super Fantasy Zone is better than everything including the arcade. Although I've always been disappointed with the plain sounds used in SFII' PCE, the compositions make it my favorite SFII soundtrack and it still sounds good. I prefer good SMS PSG over good NES PSG. Of course I like the SMS overall more as well.
Genesis FM is awesome when done right, but I find that it's not so often done
wrong so much as
imperfect. Sometimes the instruments will be unbalanced or effort was only put into the main riff or something. The sound difference in hardware variations only complicates things further (
thank god it's been sorted out).
Just as most/many developers didn't push PCE visuals in the same ways as Genesis and SNES games (
for reasons discussed many times before) most seemed content to put out great music without trying to go the extra mile creating unique sounds or using the PCE's samples capability well. The general attitude between HuCard and CD projects likely didn't help. Thankfully there's lots of cool unique sounding stuff out there if you play enough games and overall an amazing amount of quality music. SFX seem to have a better variety than music and many PCE PSG sound tests sound the same as a Genesis game sound test.
Some people have been discussing and/or judging the sound types themselves and/or the actual music. The PCE is my favorite for both. As for "redbook" music, not only do I love PCE CD music, I think that game soundtracks have gone downhill ever since. Some may not be as good as they could be, but like PCE PSG there is just so much unbelievable music regardless of the instruments used, but there is also a tonne of perfect sounding games that will never age (
Ys III, Kabukiden, Gate of Thunder, Neo Nectaris, Lords of Thunder, Monster Lair, etc).
Some PCE music samples that use sounds that are not just "beeps and boops", sometimes referred to as "FM-like":http://superpcenginegrafx.com/misc/pce_sounds.mp3