1) SEGA Dreamcast
2) Nintendo 64
3) Arcade
Shenmue, Metropolis Street Racer, GoldenEye 007 or Metal Slug on PC? 100% legal, without emulators? Great idea :)

1. Sega Dreamcast
2. Amiga
3. Commodore 64

1. Dreamcast
2. Super Nintendo
3. Nintendo 64

1) Amiga
Has good emulator (Winuae) and you actually could get publishers permission to sell those games (not happening with Nintendo).
2) Commodore 64
Same as above.
Why I didn't pick Snes or Megadrive? Because you can already buy many of the best games from Wii store (if you own Wii). And come on, playing Mario or Sonic with keyboard? I don't think so.
Everyone knows Nintendo&Mario and Sega&Sonic. How many of you have ever played C64 or Amiga games? Check out http://hol.abime.net/hol_top99.php for some good Amiga games.

1 - AMIGA !!! :D
2 - Arcade
3 - Dreamcast
And, as many have said, although it isn't one of the options: ZX Spectrum also.
GOG, you're getting better and better! Keep up the good, excelent work!

1. Commodore Amiga
2. Nintendo64 (one can hope, right?)
3. PS2 (just so many games)
4. SEGA Dreamcast

1. Amiga
2. Commodore 64
3. Arcade
(I'd really like to see MechForce for the Amiga by Ralph Reed, if anyone could locate him (if he's still alive) to talk to. Of course, he may have had to bow out under pressure from FASA or one of their new owners... But you guys are used to dealing with IP owners, right?)

Sega Dreamcast
Sega Genesis (Megadrive)
Nintendo 64

!. Dreamcast.
2. Super Nintendo
3. Neo Geo
I would actually prefer Sega Saturn to any of these, largely because it had many great games that are difficult to find, but these are my choices from the options given. Dragon Force, Shining Force 3 (all 3 scenarios while we're dreaming) and Panzer Dragoon Saga would be instant purchases for me at any price on GOG.
Most of the best SNES games are by Nintendo and I wouldn;'t expect them to license out their back catalog for PC, but I would love to see Square Enix, Capcom, and Konami games for the system return as well as Japanese games that never released anywhere else.
I love Neo Geo games, but they would need to have online play added as most of the best are much more fun in mulitplayer.

1) Dreamcast
2) Amiga
3) nintendo 64

1. Amiga
2. C64
That's it. If I want console games, I have other options (Wii Virtual Console, for example) that are more appropriate.

1. Dreamcast. I have one, but it won't last forever.
2. Amiga. Some real classics here.
3. NeoGeo. Yum.
By strange coincidence, all three of these were noteworthy for being way ahead of their respective times. The DC is the only one I still actually own, but there are games from all three which are very dear to my heart.

1. Sega Dreamcast
2. Super Nintendo
3. Sega Genesis

1nintendo64
2super nintendo
3 /
does this mean GOG is going to port games over to pc?

1) SNES
Really, I'd love to see the original NES, but SNES is still an uber system
2) Sega Dreamcast
3) Nintendo 64
Honestly, any of these systems would be a welcome addition to GOG.