I like Douban.
http://www.douban.com
Depending on how good your mandarin is, you could try actually reading Chinese BBSes, like Tianya.
http://www.tianya.cn/focus/index.shtml
If you're looking for simply sites with interesting Chinese news, you can check out Chinasmack. They also link to the original articles in Chinese.
http://www.chinasmack.com