Thanks to last.fm and the ability to auto-scrobble from iTunes/iPod/iPhone, I know that the following were my "Top" lists for 2010

Top Artists

LastFmTopArtists2010

Top Tracks 

LastFmTopTracks2011

Top Albums 

LastFMTopAlbums

I love last.fm, the fact it records this information for me, uses this to make recommendations, and lets me have access to a set of neighbours, people with similar music tastes to me - which is how I discovered some of the artists who made it into my list, is wonderful.  It takes very little effort for me to get this information, and leads to me finding new music to listen to.  What's not to love.