hentai manga > hentai anime >= real porn
any are fine but that's my preference.
hentai manga: like people said before me, more variety, stories, almost anything is possible, and artwork has idealistic and awesome proportions.
hentai anime: i'm ok with this but i do agree that the squealing gets a little annoying at times. whether characters are being raped or just having consensual sex, they're both screaming. Also animation more often than not just can't compete to the quality of well drawn manga (with exceptions of course, there are really good hentai anime out there)
real porn: ok to get your fap on every now and then, but fake repetitive moaning becomes a turn off. ugly guys that should have no business having sex are having sex.
Mostly everyone has covered this, but in the end, it's all fapping material for me. some manga are fun to read though i'll admit