The regional Finnish Usenet
hierarchy that has, as of writing, 227 newsgroups, and more is coming.
Sfnet group creation is controlled; Requests for new groups are first discussed (in sfnet.ryhmat+listat, group name means "groups and lists"), and if there's enough interest, a new newsgroup is created. (As of writinng, the address from which newgroups and related things are sent is email@example.com.)
The equivalent of alt.* hierarchy (ie, anyone can newgroup) in Finland is finet.* (though it seems to be fairly quiet).
From what I can tell, sfnet is a fairly reasonable part of Usenet; sfnet newsgroups are usually not plagued by spam (either the filtering is airtight, or maybe Finnish corporations know well enough that spam is evil), and even troll problems are usually got in order quickly. People also seem to follow netiquette pretty well. (This, of course, can be said of the group I'm reading. I know some groups have more problems with idiots. =)