As I am a writer of one, this should help :P

What makes a story really grip you on The Sims Community?

I'd say the pictures, myself, but the poor grammar some people use on here, along with punctuation, really annoys me :P

A bit of mystery. If you try and lead the readers on without revealing to much and then reveal the big secret later. Like what I'm doing in my current story (In signature)

Style. I'm into things that are not the normal thing to write about....then again, I'd say my story I'm writing may be considered normal to some..... Also pictures, I like pictures that have nice crisp appearences.

A great beginning. Not, "my name is so-and-so and I just moved to a new town and look here I am posing in front of my house." Sim stories are just regular stories with pictures - the rules of regular stories apply. How exciting is it to read a story that starts with the protagonist introducing themselves? Throw the reader in the midst of the action immediately. That doesn't mean, put in a fight scene or something, it can be a scene relaxing at home or walking down a dark alleyway at night, but as long as the reader instantly feels engaged in the story. That's what grips me, and keeps me reading. Also, a bit of mystery. When not everything is revealed immediately - like we see people or we read a conversation, but we don't know who the people are or what the context is. It can make for very interesting reading.