Oni Chichi for loli. There is incest (father and daughter) Futabu! is a really good futanari hentai, if you're into that kinda stuff. Imouto Paradise is kinda like a moe hentai. It's definitely interesting. There is incest as well (sibling) Boku no pico is a yaoi shota hentai. It's kinda boring tbh Euphoria is a nice bdsm hentai. It's pretty disgusting at times though (scat, etc) so be warned. HHH Triple ecchi is a pretty good vanilla There isn't a 'best' hentai since it really depends on your tastes. The ones listed above are ones that I liked.
By far probably Boku No Pico. Wasn't a big fan of OVA 3 though.
BOKU NO PICO