I have not had any problems with Craigslist so far, but I completely understand your feelings - if it happened to me, I wouldn't want to use them either.
Here are a few that I have found: www.maternityave.com, www.handmedowns.com/chicago (free listings, but can upgrade to premuim), www.schaumburgyardsales.com (they have this site for many other cities as well, so type in www.<your city name here>yardsales.com.
There is also a new one that just started recently - www.mom2momexchangecom, but they do charge a membership fee to list (it varies by how long you subscribe and how many postings you want - you can see the fee schedule by go to the Register link).
I don't know the success of sales on these sites. I do know that most of the items I was looking for on _________yardsales.com and www.handmedowns.com are sold VERY fast.
Good luck!