How I make my best-of playlists:
1) Make a playlist of every song added to my iTunes library in the past year.
2) Make a second playlist of only the songs that were released in the past year.
3) Choose one song per artist to put into a third, best-of playlist.
4) Organize the songs from favorites to least favorites.
The end result is a playlist of songs released in the past year, limited to one song per artist, ranked in descending order.
These lists are super long, but I figure it’s better to have more great songs and people can take from it what they want, rather than limit it to some arbitrary number. If you’re interested in the top 20 tracks of the year, check out 1-20. You can do that for the top 10, 100, 300, etc.
Here are my best-of lists by year: