Okay, I know this fad has run its course, but I stumbled upon it late and haven't yet gotten tired of it, and dammit it's my blog my rules so whatever.
Three different versions of the "Caramelldansen" video, all pretty well-done and elaborate:
The Melancholy of Haruhi Suzumiya:
The animation is kinda clunky, but I like how it follows the plot of the series.
Lupin the Third:
I have to give this one the highest mark on craftsmanship, not least because it's better-drawn than the cartoon it's based on!
And my favorite... Mobile Police Patlabor:
Dammit, I wish I had a scanner and the right software 'cause I really wanna create a DC Universe Caramelldansen video now...