if you mean a good website than i'd have to say around-the-sims. it has some of the best objects i've ever seen, and some of them are "hacked" too. this site (thesimszone) is pretty good too. if you're looking for skins, check out
http://www.allaboutskins.com. they have band skins like blink-182, incubus, marilyn manson, and linkin park. if you're not very good with files & downloading (like me, he he he) then you should download the add-on handler. it automatically installs non-official sims items to your sims games. plus, it doesn't take up space on your sims disk (neither does transmogrifier or make-a date/celebrity) without the add-on handler, the only files that are downloaded directly to your sims game without doing some weird file thing are the official sims objects from
http://www.thesims.com.