Possibly the best thing i've ever seen. I might possibly need to get out more you say, but for a dog owning Star Wars fan it doesn't get much better than this.
This may be as old as the Internet, but I still find it sidesplittingly funny even after watching it multiple times, so I suspect that even those who have seen it before will remain amused.
I do apologize to anyone who finds the subject matter of the original song too heavy for this kind of parody, but I personally find the lyrics too unintelligible to be very upset.
Edit: This one is similarly old, but I think it might be even funnier. It's a slightly different genre, but with much the same effect.