A few more. . .
Wow, keep this up and pretty soon you'll have found more than I did to get the list started. Thank you!
Great, we already have an HP Start Menu replacement on the list and you just contributed the Lenovo one. Let's keep an eye out for Samsung and Toshiba versions. (Screenshots of a Samsung start menu had appeared a couple of months ago, but I haven't heard anything new as to whether they'd gone ahead with it.)
JorgeA, from what I read online Samsung and Toshiba are offering a Start button and menu of their own (at least with particular models); although I did a quick search on their sites I came up empty.
I haven't been able to get the DeviantArt link to work for the Windows 8 Start Menu toggle (or anything else there), maybe the server is down for maintenance on Thanksgiving.