Gotta give a mention to my old work experience, HS&P, who've really pushed some envelopes with their Christmas e-card, the website devoted to their mascot. Creepy little chap, I've often thought!
The site is jammed with articles on how to embrace (or just survive) the season, each one written by different employees. I was there when the project began; it was cool to see everyone get into the spirit of the task. And the videos are hilarious. Like, deliberately hilarious.