by EkaCoralian » Mon Nov 16, 2009 10:04 pm
Episode 7 of K-ON! is basically completely dedicated to Christmas (this has a clip of Yui wobbling around the Christmas tree after placing the star on, which might be close to what you're looking for), and episode 19 of ToraDora's got a dance/swing-like thing with Ryuuji in a bear suit wearing a Santa hat.
If you want something random and seasonal, 20 minutes or so into the Sailor Moon S Movie (Hearts in Ice) has a mini Christmas reference (who could pass up a clip of Tuxedo Mask posing as Santa for a few seconds and then revealing that he's NOT Santa in an epic way? xD)