>>10 Some people honestly play it for the sex, others play them for the story or simply the fun of some of the more interactive games. For example, Fate/Stay Night has a
very expansive and interesting story and premise, and it was an absolute joy to read through simply of how the entire plot was woven (and also, the Ctrl key is wonderful for skipping the sex scenes in a lot of games). Likewise Kamidori has a weaker story, but it's a highly interactive dungeon crawler that's a joy to play, with the sex being a more on-the-side thing rather then the focus of the gameplay (and once again, if you don't want to see those scenes the Ctrl key works wonders).
Admittedly, there are a lot of trashy games out there, where the sex is the main focus and the plot is about how to get it, but there are other erotic games out there which don't focus on it, and may even have a plausible reason for using it to drive a plot point (Yume Miru Kusuri actually has a lot of subtext in said H-scenes which displays the state of the relationship between the characters, along with the emotional and mental state of the heroine, rather then being "Oh, sex is great. Gotta have more sex").
Basically, a good guideline to go by is a story/plot-to-sex ratio. The lower the ratio is, the less likely it is to be worth your time unless you're some kind of sex-hungry nymphomaniac. Most, if not all, threads on the board are about games that are high on the ratio (or the ratio may be non-existent in some cases as sex=0), so as long as you remember that most games will let you use the Ctrl key to skip scenes you'll be set to explore any of these titles for the story behind them rather then going "OH MY GOD, A PENIS. THIS GAME IS THE WORK OF THE DEVIL!" (yes, obvious strawman, I know)
Oh, there IS one exception to the whole story-to-sex ratio though - Sengoku Rance. It doesn't have a thread here (yet), but it is a truly enjoyable strategy game, even if the protag is a sex-hungry mercenary with his own sex-slave, out to have sex with as many women as possible
simply because the strategy game is so deep and intricate, along with the Ctrl key working again and it having some absolutely priceless humor.
Then again, this is an opinion piece. tl;dr version: I play this stuff for the plot or because it's legitimately fun, the sex isn't important in any manner whatsoever (unless it's a good game and the sex is a plot point - because then the sex becomes part of the story :V).