Here's a USA-market Sega Genesis CD-X, with a bunch of games and accessories (as shown).

I've tested a lot of the gear - the controllers seemed OK, the AV cable is fine. I didn't check the modulator as I don't have an NTSC TV (though should work on most modern TVs). The game CDs look amazingly good, I would guess that most have never been used; some cases have cracks but this looks a lot like it's from storage.

There's one fault I know of: the CD-X only runs when it's sitting on its side. Sitting flat or on the other side, it won't load disks. Some time ago I asked someone knowledgeable about Sega machines, they said that it was probably the rail the laser carriage slides on that needs cleaning and/or lubrication, but I'm not going to go to that extent myself. The laser is obviously fine, which is the main thing.

Video (I dusted the machine after this!): http://www.youtube.com/watch?v=E0BJQl4iCAk&feature=youtu.
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Included is as you see in the pics, for example:
CD-X
Two six-button controllers
NTSC modulator
A/V stereo cable

Games:
Ecco the Dolphin
Sonic CD (2 CDs, multiple games I think)
Thunderstrike (two copies)
Silpheed
Afterburner
Rise of the Dragon
Ground Zero
The adventures of Batman and Robin
SoulStar
Joe Montana's NFL Football
NHL '94
Cliffhanger
SubTerrania (cartridge)