Just like last year, the site Fimoculous.com is compiling end-of-year lists for 2007, from all over the web. Already a decent-sized list, I'm sure there'll be plenty more to come. You can see them grouped by category, source, or date for your conveniences. Recently lots and lots of lists from Time and New York Magazines.
Some of my favorites so far: Time's top television ads and top viral videos, and New York Times' Year in Ideas.