Cheapest out of the box XBMC device?

Hi all.

I have a full blown HTPC for XBMC, but I now want to add a cheap plug and play box that wll sufficiently decode 720p on XBMC. I am just learning that there are little android based boxes that come with a remote and can handle XBMC on them. But I don't know which one(s) are most liked here on the forum.

Any advice would be greatly appreciated.

Thank you.