They aren't really rare, but I have all these systems complete in box:

Sega Saturn (Model 1) (x2)
Sega Saturn (Model 2)
Sega Master System (SuperScope 3-D)
Sega Master System (The Master System)
Sega 32X (x2)
Sega CD (Tray)
Sega CD (Side loading)
Sega Genesis (Model 2 Core Edition)
Sega Dreamcast

Nintendo 64 (Launch)
PlayStation (Launch)
PlayStation 2 (Launch)
Super Nintendo Entertainment System (Launch)
TurboGrafx-16 (Launch)
Nintendo Entertainment System