Share what you liked, it might help since there is a lot of crap out there.
One of the earlier TG story sites I got hooked on was http://tsa.transform.to/ Unlike later TG sites, the guy running it wouldn't post stories unless he had at least spell-checked and maybe proofread them as an editor. (I see Doc's Lab as his closest successor, and I'm glad tfguy rejected a couple of my submissions before.)
At the time I also tried visiting Crystal's Story Site, Sapphire's Place, a lot of miscellaneous homepages in English, and later TG story site, and Writing.com, but I can't recommend them.
In fact, for a few years I didn't really rely on any site, and I just did complicated google/yahoo keyword searches that I thought would give me the kind of tg story I wanted, like, "Long haired, girl's body, switched bodies, myself, mirror, bath, author, by, story."
I lost my better Fictionmania links, if they ever existed. I do remember liking Amy Komori, for the non-h lesbian age-regressed Japanese living in the Southern US, but I lost interest because it never ended as the slice of life story continued.
