For me, it depends on me. Sometimes i want to play a H-Game only because of the Hentai Content than Animation goes first. But sometimes i want to read a good Story than i prefer the Artwork.
Animation's good, but story, character interaction, and good artwork are a must. Less so on the artwork, even. Take Tsukihime: heavily censored with relatively few sex scenes, but the endings are enough to make one weep out of sadness or joy.
I prefer the animation (something for my eyes to follow) as often stories tend to become predictable / repetitive which would make me sad (they're not blood related, child classmates, etc, etc).
Occasionally there will be the gems but sifting for the gem does tend to be time consuming