Recoloring furniture, clothes -- well, just about anything, really -- is made easy in "The Sims 3" by using Create-A-Style. Completely new furniture sets are a completely different animal. TSR Workshop, create by The Sims Resource, is a third-party tool for making new furniture. The fan sites listed below use that tool to create fabulous object downloads.
Join The Sims Resource to download furniture made by anyone who wishes to submit to the community web site. Some items are free. Others require you to subscribe to The Sims Resource. Members have access to furniture, clothes, sims, and house downloads. Quality varies, but is worth digging through the pages.
For a little bit of everything go to Mod the Sims. Here you will find the everyday furniture items and buyable versions of items normally not found in build or buy mode.
Artwork using standard game meshes and new meshes. The style is modern and classic. Artwork here should fit right into most of your Sims' homes.
Around the Sims 3 continues their tradition of quality downloads. Collections of coordinating recolors are in the objects section.
New painting meshes with paintings that could easily be placed in the majority of Sim homes.
Mango Sims offers up furniture sets that come with a mixture of recolors and new meshes.
Verona Relapse focuses on making paintings. Modern prints, vintage child's pieces, comics, and more.