The Town that Santa Forgot was a mainstay in my household, I always thought it was better-known classic. I always thought the ending where he becomes second-in-command to Santa Claus was a little strange.
While it's not "strange" so much as interesting- Ichigo Mashimaro's last episode is a Christmas episode and is very "Specialy" in regards to it being heartwarming and about the spirit of the whole thing. However, it's also quite funny at times and interesting because it's set in Japan and you get a glimpse of what it's like there. The only problem is that it is the last episode of the series and you're expected to know the characters more, but it's not too inaccessible.