My favourite tag would either be elf or catgirl.
Catgirl because, I love me some cute catgirls. I love cats, I love girls, why not both?
Also because it's often stories of stray kitties or just somebodies cats that have somehow humanised and want to show their appreciation to their owner/ master. Heart warming stuff. But questionable if you look at it from another angle, but we actively avoid that angle, much like the angle showing the top of the rear quarter panel on an s15 silvia.
And elf, because they're quick to recognise lewdness.
Also because they've usually got interesting back stories regarding the villages, and then lore about their people and what not. Which is all really interesting, considering it's given to you in like 2 or 3 pages. But still detailed enough to give you the info you need.