Not much, unfortunately. Most old games like Star Raiders, Defender, etc. will run in 16 kb, but most of the games need at least 48 kb of RAM.
Atari ST/E', Mega ST4, Amiga stuff, a newly built Amiga 500++ with TF534, 1200 with 4 GB CF, Blizzard 1220/4. Atari 8 Bit Stuff, a modded 600XL with Ultimate 1 MB and Sophia RGB, 130XE with 320Kb RAM and Sophia RGB and a stock 800XLF. Some Commodore 64's, one modded with JiffyDOS switchless kernal switcher and an Ultimate64. Sinclair ZX Spectrum stuff, some self built clones. That's it, pretty much.