I bought a MiST FPGA a few months ago in order to get that "instant on" experience that you just don't experience with emulators on PC/Mac.
At the time, MiST had hardware emulation of the Atari ST, Amiga (MiniMig core) and Atari 8-bit.
It's darn cool. There are occasional compatibility issues with the ST and Amiga cores, but the Atari 8-bit core hasn't failed me yet.
On top of additional Arcade, C64 and Spectrum cores that have appeared, it's now running an Apple II core as well. I successfully loaded Drol last night, but there are still a few issues with the joystick to work out.
Cool stuff. Thought a few people might find it interesting.