Nothing I would register and surely nothing I would buy
I like industry keywords com/net/org
I like a few prefixes of keywords same
.us and .biz have some value if an industry keyword
.co.uk
.ca
solid country tld's
the rest I'm not a big fan of, .com is king and net/org/us/biz are all okay to develop in
I only have interest in keywords for industries or professions that have high cpc value and lots of searches on
sure some have done well in lesser domains but if it can't sell for a lot, I have little interest in it