I post lists of every single fanfic I read, and mark the ones I recommend as "Recommended" or "Highly Recommended". I also post mini-reviews in which I might mention the sort of things you're discussing here... for example, I might say "OMG, this was a fantastic concept and I love this pairing, even if it could've done with a spellcheck. Recommended (but only if you don't twitch at unbeta'd fic)." I'm sure you've seen me do it. But, see, I'm not really in it for the reccing, and I say so up-front, and also warn readers that if I don't like something I will say so, so it's a bit of a different situation.