1. Amiga
2. Nintendo 64
3. Sega Dreamcast
My top choice, personally, would be PlayStation One, though :)

1. Sega Dreamcast
2. Super Nintendo
3. Neogeo

Sega Genesis ?
but you can buy those games on GamersGate and Steam
1. C64
2. Amiga

1. Sega Dreamcast
2. Arcade
3. Amiga
I choose these because the C64, Genesis, Neogeo, SNES and N64 all get releases on the Wii's virtual console, so the arrangement would be less exclusive and far less interesting. Furthermore, I never actually owned a Dreamcast but still would like very much to play a number of games from that era. The arcade and Amiga options were simply plugged in as filler, but I don't have any substantial interest in either (though I'd rather see either of those than the rest of the choices that were not listed).

HOLY SHIT!
1)SNES
2)N64
3)Amiga
OH PLEASE MAKE IT HAPPEN :D :D

1. Arcade
2. Mega Drive
3. Amiga
Those platforms are a mix of ultra-popular and not-so-avaiable.

1. amiga
2.arcade
3.Commodore 64

1) Mega Drive
2) SNES
3) Amiga
I want to relive my childhood

1. Sega Dreamcast
2. Neogeo
3. Sega Genesis (nostalgia's sake, used to own one)

C64 (well, C128 but games are the same). (The Detective, Last Ninja and tons of others)
Atari (why is it not on the list?)
and those Amiga games which were not available on PC.
And I like the idea of GOG going in that direction. I hope the prices won't be ridiculous,
ps. I really like this idea, but there are still thousands of PC games that needs releasing here. Please do sign LucasArts and EA this year.

Sega Genesis
Super Nintendo
Nintendo 64

1. NeoGeo
2. Dreamcast
3. Amiga
NeoGeo and DC because they're not easy to come by for a cheap price, and then Amiga because that's the platform where gaming really matured and games evolved into something that still looks good, as well as plays good.

Speccy, Speccy, SPECCY!!!

All of the above.

1. Dreamcast
2. Amiga
3. C64