If the Alan Kimmel circlotron had been on your list I would probably have voted for that. I opted for "own design circlotron" as the closest choice.
Putting my money where my mouth is, currently acquiring parts to build an Atma-Sphere clone. I expect this to be my "retirement" amp, so I'm trying to do it as well as I know how.
Critical issue is determining which speakers you want to use. OTL's can be picky, especially with speakers that have impedence that varies wildly with frequency. I'm currently looking at some Audiokinesis Planetariums, which seem to be a great match for the OTL.