1. Amiga
2. Commodore 64
3. Arcade

1. C-64 (I so, so miss Mail Order Monsters!)
2. Arcade
3. Super Nintendo

Sega Dreamcast please, the others are too easily emulated and I already have the whole snes\megadrive romset.
Amiga would be nice too

1. Super Nintendo
2. Nintendo 64
3. Megadrive
If it were possible, I'd love to see PS1 games made available, such as the old Final Fantasy games, however I'm sure that's probably not a possibility since Sony still make money from these games on the Playstation Network Store. Oh well.

1. Amiga
2 .Super Nintendo
3. Dreamcast

1) Sega Megadrive
2) Sega Dreamcast
3) SNES

1. Commodore 64
2. Amiga
3. Arcade

Incidentally, FF7 and FF8 have native PC ports.

1. Super Nintendo - earthbound.
2. Arcade - cause we love arcade games, but hate paying out our paychecks in quarters.
3. Dreamcast - a few games ive been wanting to play on it, but its impossible to find.

Sega Genesis (Megadrive)
Super Nintendo
Nintendo 64

1. NeoGeo
2. Arcade
3. Dreamcast
I say this only because of the lack of availability of a lot of the titles through any other means (emulation, DLC re-releases by current IP owners, etc.), controls would be a potential issue as far as optimal enjoyment goes, but better the games are out there than not, I can always go dig out my PC gamepads that haven't seen the light of day for around 8-10 years. Amiga and/or C64 would be decent too though.

1. Sega Dreamcast
2. Super Nintendo
3. Arcade

Dreamcast
Arcade
SNES.
I know the SNES might be a touch harder to do, but DC and Arcade come first.

1. Nintendo 64
2. Amiga
3. NES

1. Amiga
2. Dreamcast
3. N64
There are so many awesome Amiga games that could be reincarnated. The Chaos Engine series, It Came From The Desert and Valhalla come to mind!