animation just doesnt have the same feel. especially these days where every hentai animation feels cheap besides the few rare ones and theres not as many genres...where the fuck is my monster girl hentai, yuri and futa!?
In my experience hentai anime tend to have sparse animation and ugly/bland artistry because they are made on a low budget. That tends to suck out the sexiness to me. It's also harder to find a hentai anime with a good story than it is in the manga format.
On the latter point I might be biased because I read manga here on FAKKU, and Jacob has said that he judges hentai on how good the art and story is. Still, I don't know of any hentai anime that's as ambitious and impressive as any of the FAKKU Books. I'm not sure if this is unique to hentai as manga does sometimes seem to be a medium that due to its nature allows artists to have more freedom and get away with more than what they can in anime.
I will say though that there is a hentai anime that I love: Sexfriend. It's an OVA series (2 episodes) based on an ero-game. The animation and artistry is not anything special but it's done just right to make it very sexy, and the story is good too. Whoever made Sexfriend seem to have put some more effort into it than what's typical for hentai anime, and I highly recommend it.
I'm a Manga/doujinshi master race kind of guy. The art is generally higher quality, the arousal factor is just higher usually, and the quantity and quality just gives manga the upper hand. That said, I really like some H-anime like Kiss_x_Sis with some good OVAs and a dozen other anime series I can't currently recall the names of that are of that same quality.
I voted for hentai manga since there is no option for both. There definitely is hentai anime that I love -- ones that come to mind are Oni ChiChi series and Imouto Paradise 2 -- and I would have liked to be able to vote for the h-anime as well.
Manga by a long shot. Some anime will be a timeless fap for me, but the state of the hentai anime industry in general is just bad right now, in my opinion.