Two things that have annoyed me while looking around on SLS:
1. Pictures of, say, just a woman's feet. Yeah, some people are really into feet, but I'm going to guess that feet rank pretty low on most people's priorities.
2. The "I'm hiding myself" pic, as seen on myspace. Look, if you're not happy with your body, say you're overweight, you might be able to partially disguise your body type by holding your camera up over your head and shooting down so as only to show face and breasts. This might work fine for you online, but if you meet someone, they're going to see what you look like anyway. Besides, when I see such a picture, I just say, "Trying to hide, I'm moving on".
That's why my SLS main picture is a clothed full-body picture with my head shopped out.