Refdesk has a list of "2010 best in * "websites that is as comprehensive as one would expect from this excellent site.
Some of my favs from the list are:
Google: Google's Top Searches - Year-end Zeitgeist for 2010
NPR: Best Books of 2010
National Geographic: Best Photography of 2010
New York Times, The: 100 Notable Books of 2010
New Yorker, The: The Best NASA Photographs of 2010
Popular Science: Best New Innovations of 2010
Time: 50 Best Websites of 2010
