I love this one as you can upload your own pictures and make them into puzzles. It's free!
http://www.jigidi.com/
Someone is making the Farmer's Wife Sampler Quilt and is uploading the blocks as puzzles as well as other quilty puzzles, fabrics, pets, great scenery, etc. I have only seen one offensive puzzle but I think it has been moved over to the unfiltered side. I have my filter set so I only get the wanted G rated puzzles.