I went for FPGA Arcade, though if it turns out that Natami isn't much more expensive I will get that instead. Natami looks to be much more powerful than the Arcade, but I doubt I will be able to justify the extra cost.
I would be a bit surprised to see anyone voting for Minimig, as while it was a tremendous achievement at the time it will be a bit redundant once Natami and FPGA Arcade are out. The only advantage it has is that it is available now

EDIT: Sod's law that as I typed the above someone voted Minimig!