I have often heard about Milton Green's 1964 TMs, but found it hard to understand their behavior based on Green's short write-up, so I spent a little time to analyze the machines myself. These TMs turned out to be more clever than I expected (especially the odd sized ones).
Additionally, I don't know of any TMs that beat the 9-15 state Green Machines. Are they the reigning champions for BB(9) to BB(15)? Let me know here or in my *new* comment system on my blog (just set up today) :)