While the heyday of the Sims has passed, Kieron Gillen has posted a (lengthy) piece on 'Sex and the Sims' over at Rock, Paper, Shotgun - an essay that was supposed to be included in a project that was cancelled a while back. It's a meditation on (of course) sex and the Sims, but more broadly about connection and interaction with games. Well worth a read if you have the time, even if you're one of those people who never quite got the appeal ...
The magic of The Sims is that you are both in control and not in control. You can live out your fantasies, imprinting on these fictional characters, deciding what they'll do next, but you can't be sure if it'll all turn out okay. In the moment between ordering a Sim to kiss and seeing the response... that's where the erotic sparks. It's not the animation that's the pay-off - but that you were accepted, the seduction worked, they wanted you after all. And it's not that you've kissed someone, but you know who that person is due to having spent so much time in their simulated company. The Sims is sexy because it creates a complete naturalistic context for it to occur in.
The idea that video games are 'most enthralling when you're least in control' is an interesting one (the author points to the horror games, where the fumbling during the learning curve makes everything that much more terrifying and immersive) - and unlike career choices or bricking your Sim up in a room to die in a puddle of filth from starvation, romantic aspects of the Sims remain one area at least partially out of the player's control. It's an interesting theory, and one I'm willing to buy into at least partially.
ErotiSim: Sex and The Sims [Rock, Paper, Shotgun]