I also run my own little list. It's not as long as Jana's, but it's also easier to search and isn't restricted to manga and anime.
In fact, there are only four rules limiting what goes onto it:
- With a small exception for the "hearsay" section, I have to have seen the thing to confirm it's content and categorize it.
- Because Farhad's TG site has so darn many ecchi and hentai doujinshi, I've decided that, until I can switch to a DB-backed system, I won't be listing adult materials unless they have a notably good plot.
- The Fanfiction section lists only stuff which is the exception to the rule... so no Ranma fics unless they gender-bend someone who normally isn't.
- Because it'd flood out the rest (and because much of it has no stable URL), my collection of TG images is available on request only. (I push a roughly 150MB zip file onto somewhere like MegaUpload)
It's at
http://www.ssokolow.com/List_of_GenderBending and I also took the liberty of adding Jana's site and TG Taizen to the "sites" section.
Oh, I should probably mention that there are between one and two dozen other manga that will go onto the list as soon as I can spare the time to read them. (And at least that many fanfics worthy of being on the list that I still have to rediscover by backtracking all the fics I've read over the years)
Finally, I know there was a third list but it's not easy to find via Google and I'm still sorting through thousands of bookmarks.