I have a folder on the iPod with Christmas music. I list the year on each song as "2512" so I can delete them all at the end of the year. I usually put them in during the first snowstorm of the year (early November this time around). And it usually becomes my default listening from then until the end of the year.
How many songs are in the folder? About a thousand. Seriously. I just really like holiday music. I tend to like a few types of songs. Classic music done by orchestras (101 Strings, for instance) and choirs (Vienna Boys Choir). Vocal numbers by singers from the 40s through the 60s (Andy Williams, Perry Como, Julie Andrews). Weird "original" songs (although I seem to be alone in thinking "Christmas Unicorn" isn't the best holiday song recorded this century).