I have two "want" lists for #retrocomputing. One of them is the practical list, the things that are realistic to find at some point. The other is pure balls-out insanity.

Practical:
• Tandy 1000HX
• Atari ST
• Rubber keyed ZX Spectrum 48K
• Amstrad 464
• IBM PC XT
• One of Serget's 8088 clone builds
• A Sun SPARC workstation
• Apple IIe Platinum
• A Commodore PET

Insane:
• An SGI workstation
• A Unisys ICON (VERY rare)
• Altair 8800 or IMSAI 8080
• Some type of cabinet-sized minicomputer