I got a Multiple Classic Computer over the holidays, and I am impressed with it. It's an FPGA that uses "cores" to emulate various 8 and 16-bit computers quite well. It currently supports Amiga and C64 with good compatibility. The Atari 2600 core is in development, as well as the Apple II core that lacks supporting disk images.
Everything is stored on SD cards and the whole thing is powered with 5v, and I got the version that outputs in VGA.
I recall seeing these at the Midwest Gaming Classic last year and being put off by the price, but it really is worth it for Amiga alone. I really hope that more cores come out supporting tons of classic computers like the MSX, BBC Micro, and Atari ST.
Here's an example of it running:
http://www.youtube.com/watch?v=-ij0krcaGvE
Anyone else have one of these or any other reimplementation of a classic computer like a 1ChipMSX or Minimig?