Santa Claus is Coming to Town (1970)
A pity: it's actually one of the better ones. Actually, there's a case to be made that it might be the best.
"Santa Claus is Coming to Town" borrows heavily from L. Frank Baum's writings on Santa (the orphan adopted by elves and even aspects of his capture all seem to have come from there). Of course, Baum's work would later be adapted more directly in the aforementioned "Life and Times of Santa Claus," but that's irrelevant, since hardly anyone's ever seen it.
The aspects of "Santa Claus is Coming to Town" that seem to strike a chord are the Winter Warlock and the Burgermeister Meisterburger, the special's two villains. Actually, only the Burgermeister actually deserves the title "villain," as the Warlock changes sides almost immediately.
I love the character of the Winter Warlock, whose two sides are a great personification of the bitterness and gentle beauty of the season. I have somewhat mixed feelings on the Burgermeister, who seems a tad... silly. I appreciate that was the intent, but a slightly more menacing figure might have paid off here.
Ultimately, the Burgermeister is a stand-in for the Sheriff of Nottingham, since this Claus is more or less based on Robin Hood. It's been said a hero is only as good as his villain, and I think a stronger nemesis might have made this one a bit more memorable.
The main reason I defend this, though, is Jessica, their version of Ms. Claus, who, of course, is more than a little reminiscent of the Maid Marian. The love story between between her and Kringle lies at the heart of this special, and I find it genuinely touching. The marriage ceremony, in particular, is a beautiful scene, and the Winter Warlock's role literally brings a tear to my eye (yeah, I'm a sucker for this stuff).
I also love that the solution to the Burgermeister is to outlive him. No glorious end for him: Santa outlasts him and becomes a legend, while the Burgermeister is forgotten. If the story had revolved around his conflict with Santa, I'd call this a letdown. As it is, the Burgermeister is more of a sidenote: the story is about Kris and Jessica.
And I'm of the opinion it's a pretty good one.