I love Rudolph The Red Nosed Reindeer, but no matter what, The Year Without A Santa Claus will always remain as my favorite Rankin/Bass Christmas special. The Miser Brothers are great, its extremely charming, and I'd argue the best animation out of the Rankin/Bass specials. If you love Christmas and the Rankin/Bass specials, like me, then I'd request to give this a watch.
Review of The Year Without a Santa Claus
