The 1000 Most Visited Sites on The Web
Adam Rifkin stashed this in The Web
DoubleClick AdPlanner by Google keeps track.
Facebook has 880 million unique visitors per month and has 1 trillion page views per month. That's more than the next 99 sites combined.
#2 site YouTube has 800 million unique visitors per month and has 100 billion page views per month. It's not a fair comparison since those are mostly streaming videos, but still: one-tenth the pageviews of #1 Facebook.
Several of the top sites are Chinese. Expect this trend to go deeper.
Yahoo.com > Live.com + MSN.com + Microsoft.com + Bing.com + Windows.com. Microsoft has 5 of the top 21 websites but Yahoo is still way bigger than all of them combined. And that doesn't include Yahoo Japan, which is #28.
Twitter is #15 with 160 million unique visitors per month and 6 billion page views a month -- without counting mobile stats. Mobile probably makes Twitter a lot bigger.