Parsimonious is a huuuuuge site with both sims1 and sims2 content; highly original, colorful content that works well in the game. They also have things that other sites often lack, such as a volume of clothes for elders and childrens furniture and clothes.

Simthing for Everyone is one of the older sims site and has seen a few incarnations, although the main themes and the quality have been consistant. It's a fun site with more than just downloads - check out the stories for a laugh or two. Make sure to explore, there are gems throughout the site.

Around the Sims 2 is one of my favorite sites and I have a lot of Sandy's content in my game! There are many, many different new mesh and recolored whole room sets to choose from. The vast majority of the content is free with some specific pieces reserved for donators.

Pixel sims, as far as I can tell, is not actually updating anymore. However, the custom windows and doors are really great. Helena's very generous file sharing and builder friendly policies, make her creations easy to use in houses and lots as well.

HoneyB's many websites start from this page - there is a list of free sims sites (The List), as well as the Drop and the Basement which contain free downloads. Plus there are links to the yahoo group and The Swarm which is the B-List forum. It's been a while since an update, but the forum has some activity still.

Holy Simoly! Holy Cow! Turn your pop-up blockers on and make sure you are running adaware and maybe a good virus program, but then do go visit this site. Another file share friendly, lot builder friendly site with lots of awesome content. Their objects and wall and floor textures are really fantastic. Unfortunately when I visited, there were also lots of rotating (and spawning) ads. Be aware, and then go download!