my experience with gg's site is that he send superb all over traffic and lots of traffic...as far as productive traffic I've found jay's traffic to be the best so far and he sends bundles of it too
Penisbot sends the most for hentai \ cartoon \ anime stuff...kicks all the other major linklists' ass combined when it comes to that niche.
one neat trick I usually do is search for terms related to the niche in Google...for example if you search for "hentai porn" on google you will find penisbot being #1 and Greenguy being far up there too...so its safe to assume that these two sends reasonable amounts of hentai niche traffic
atleast this is what I do when I venture into new niches and it seems to work great