thanks for the info. there should be a dedicated wonderswan tracker similar to famitracker or rmt

I also like the ADSP series of chips. these chips were used in several Leland and midway arcade games. fun fact: one of those chips was also used in the dectalk synthesiser.

I like the sound of FM when it's done right but most people kinda get boring with it, and especially having FM alone is just meh. I like a PCM or something channel to be thrown in there. The soundtrack I'm currently liking is After Burner 2, track 9, After Burner, Melody Version, ripped from an emulated z80 on a 3DS. Which since YouTube isn't helping me today sounds like this. That's a YM2151 and a Sega PCM. If you're not a chip freak don't let that square wave fool you it's actually being made by the FM chip! YM2151, which seemed to be very popular in arcade games, only had FM, no PSG in it. You can tell the square is FM by listening to the way it decays, it's not just volume it's actually getting duller. Wavetable chips are cool too, and for the mml programmer they're easier to get a sound out of than FM. I can take this audacity plug-in and plop a wave file I've pre-cut and sampled into it and it spits out some numbers, which I can configure what chip they're for, and plop it into an mml file. FM ain't near that simple, and when using mml and not a tracker of some sort with live preview you spend forever just trying to get the sounds you want, and FM drums? I could never grasp how the hell you make those. The C64 was feckin' cool too in it's day, the amiga as well. The Amiga could have been so much more if people had just employed software mixing, it truly was a fully capable sound card which if you had the power you could mix a fuck ton of sounds on and avoid the resampler. But nobody did, maybe the CPU was bad enough that you couldn't do software mixing and run a demo/game at the same time. Some mods do use both channels with one sound to do panning and stuff but overall they use them all separately. And they are actually supposed to be hard left and hard right, they end up being halfwidth because the hard panning can be hard on the ears when listening through headphones. I think most people had speakers on the thing. Wish I could make a SID tune with mml, but the only compiler for it, XPMCK, has the shittiest c64 implementation it could ever have. I do like it's FM implementation though where you actually use mml to poke the registers, instead of either poking the registers directly, IWW! Or using the PMD style tone envelope definition, but I'm getting into something called mml2vgm so I have to get myself comfortable with the PMD format. I also have PMD, Dekyo might like/know that one, but I'm so used to ppmck syntax it's a bit of getting used to. Not as bad as mml2vgm though, there's something about apostrophes and envelopes are all weirdly defined using this extended ADSR shit and you don't have @v anymore, and I really need @v. I mean I guess since the majority of those chips are FM I don't have to use @V everywhere but for PSG's and wavetables it'd be nice as an alternate. Also documentation isn't in English and it's got this command chart that even the people who can see get head aches from the thing. Nasty. Wish it was an html table. Anyways I'm rambling about mml now but yeah those are the ones I like. I like the sound of FM chips, but programming them is a bitch. I can't even imagine raw register poking, surely even game composers didn't have to do that though because drivers. Basic PCM chips add a litle flavor to some FM sound, the combo can be good. Genesis had a great combo, had a blippy little PSG for sfx and some really retro sounds, though the noise generator sucked ass, an FM chip with not too many, not too few channels, and that little DAC for ya drums. Amazing to see some of the soundtracks made for that thing, and people to this day are still using actual! Genesis hardware to make music.

I also like the miki chip used in the atari lynx, and the jerry chip used on the Jaguar. the former is quite similar to pokey, while the ladder is closer to Paula from the amiga.

I also like the beeper chip used on the zx spectrum 48k.

@americandaad2005
The Beeper chip is certainly an interesting little beast, and people have made some rather interesting tunes with it.
Another favorite is the D1867G, which was the soul sound hardware behind one of the most famous toy keyboards of the 80s, the CASIO VL-1, or VL-Tone depending on where you live. The instrument sounds themselves were mainly just filtered pulse waves with different tones, and you could also program your own instruments by using the keyboard's built-in calculator function. It could also generate noise, though that was only ever used for the famous rhythm sounds themselves.
This next one is in the PSG department, it's the DPC (Display Processor Chip), which was only ever used in one game, and this provided the Atari 2600 with improved visuals, and additional audio capabilities. It was used in Pitfall II: Lost Caverns to provide background music during gameplay. It could only generate square waves.
The SSMP (which probably stands for Sony Sound and Music Processor) was the main audio unit behind the SUper Nintendo and Super Famicom. With 2 chips, the SPC700 and the DSP chip, I've heard some amazing stuff with that chip alone, such as Donkey Kong Country and Final Fantasy VI. It also had a built-in delay function to go with it, which was put to great use, especially in the Final Fantasy games, and even in Chrono Trigger. It's also very accurately emulated in the 2.0 update of Plogue's chipcrusher. Not surprising since they always take pride in very accurately emulating sound chips and their small details.
Since we're on an FM craze here, I'd also like to mention that I do enjoy the sounds of the Yamaha sound chips such as the YM2151, the YM3812, the YM2413, and the YM2612. While this isn't a Yamaha chip, the VRC7, while technically a derivative of the YM2413, sounds pretty good too.

btp chip demo:
https://www.youtube.com/watch?v=Eewsw9LWxqQ

Update: the chip I called btp is actually dpc+. btp was the name of the sound engine used.

@FamilyMario: I have actually known two different toy keyboards with those exact demo songs. If I remember well, the order would be "Jingle Bells", "Santa Claus is coming to town", "Spanish Coffee" and finally "Let It Be". One of the keyboards had a behaviour that I wouldn't be able to explain, if you would push the volume to a certain level, the pitch would go up. I really wonder why it would happen.
Edit: I remember there was also Vivaldi's Spring as a demo song between "Spanish Coffee" and "Let It Be".