Well... What does GP32 do?
It plays its own games (obviously), which include minesweeper, solitaire, and countless tetris games, along with a few others (plus a very nice port of solitaire). More stuff in commercial, but for me, that isn't its strength.
It plays SMS and GG roms at full speed with sound (although no FM emulation), and TG16 games (not quite everything, but most) with same - full-speed and sound. TG16 doesn't save as yet, but to be honest, there aren't many games for TG-16 where you *can* save, so its not a huge problem.
Gameboy games are varied - it plays some full speed etc, but others not. Some people have serious trouble getting the GBC emulator to work, too - although I've no idea why this is; perhaps some GP32s can't handle non-standard speeds of CPU very well (i.e. anything but 132 or 66), and flinch at the thought. Not sure. Anyway, they're generally good, at least for me. Apparrently it doesn'tm always read from the save-files of some games properly; I've yet to rnu into the problem, but that could just be the games I'm testing.
ScummVM is great. Although kinda varied again. When I first played it it was smooth beyond belief; now it seems to be kinda juttery on the 133MHz version (which is the one you should use idd), where it wasn't before. I've got a feeling that's something to do with the fact that I'm using it in the modded f/w, since that's the only change I've made since last I used it. However, sound needs a little bit of work as yet. But very very fun playing DOTT on the train
Sarien, I haven't tried... I imagine its too annoying to enter the stuff into the text-entry bit. Still, if you like the Sierra ega games more than the Scumm ones, its a good thing to have.
DivX is great... I've so far been reminiscing over cartoons of yore. It takes a while to encode the things, but no pain, no gain etc
.
What else is there... Oh yeah - SNES emu. Well, atm you've got two options; either you can play it full speed but without L and R, Sound, or saveing, and with lower compatibility (atm). Or you can play games slower either with or without sound (sound = speed hit), and with save available - depends on the emu you're using. The private ver of Snesemu by Zardoz is supposed to be exactly what everyone wants - full speed, sound, save, etc, but its not out yet. Still, I'm sure its possible.
NES emulation is sub-par for many games and fine for others; really depends on the game you're talking about. SMB 2 is good, but SMB 1 and 3 are both very slow with bad sound. Again, I'm certain it'll get better.
And that's just the end-user stuff (and at that, what I can remember - I've left off C64, Plus/IV, Dragon emu, MSX 1/2/+, and wonderboi, and prolly a few more at that), there's also a supported Dev community. Which can't be bad
Convinced yet?