What should the site be called?
Our site's official name is now “Science Fiction & Fantasy”. That's quite a mouthful, and it doesn't even convey the site's topic that well — on the surface it includes alternate history, horror, slipstream.
“Speculative fiction” would be a more accurate description, but it's not a well-known phrase, even amongst SF aficionados.
“Sci-fi”, the original name, is nice and short, but seems to exclude fantasy and other SF subgenres. It also evokes B-grade science fiction only to some people, so that's no good.
SFF, the current abbreviation, is not very telling: SF is a commonly-accepted abbreviation for science-fiction or speculative fiction, but SFF receives blank looks. Unfortunately, in a Stack Exchange context, “SF” evokes Server Fault, so there's potential for confusion here too.
Is there a better name for the site?
Note that this isn't about a domain name. The domain name would remain
something.stackexchange.com, possibly with aliases. This is about what visitors would see in big type on the front page, and about how we'd encourage people to mention the site.
What other Stack Exchange are doing: most are called “something” Stack Exchange, but with a single-word “something”. A few have an extra name, e.g. Apple is officially Ask Different. English is formally “Engish Language & Usage”, but “English” in a Stack Exchange site name context works. Home Improvement can be abbreviated “DIY”.