7 Deadly Sims: Provides skins, floors, walls, new and unique objects, and other add-ons based on the seven deadly sins

Mod The Sims 2: A site featuring modifications to overall game-play, skin, housing, and object downloads, and community forums for The Sims2

MySims.com: Official site. Information, screenshots, newsletter, and a video

The Sims Bustin' Out: Official site. Provides features, screenshots, media, characters, locations, objects, articles and a community

TheSims.com: The official site by Maxis, features exclusive downloads, contests, news, BBS, chat, and a Sims Exchange