Even though I am a recovering weab, I am finding that the tag that I get the most use would be 'Japanese Game' as it generally increases the chances of:
A - A game having an actual gameplay loop of some kind.
B - Being feature complete (minus a couple of bugfixes/minor updates at times).
C - Content that requires saying "... the fuuuuuuuuuuuuck?" at least once.
Key words being "increases the chances of" mind you, as they are not all bangers. I'll definitely tip my hat to Miel's naming game,
as I do love me some alliteration, but downloading and clicking through their catalogue is definitely not going to happen (On the other hand though, the WolfRPG prefix has yet to disappoint me).
Other than that one specifically, I tend to stick to the technical tags to filter things out as they're usually hard to argue. Actual content tags have too much of the Princess Bride's "I don't think that means what you think it means" to be of use to me, and I'm not just speaking about this site when it comes to that.