WARNING: NOT SAFE FOR WORK!
This one is a year old, and has gotten well over 4 million hits on Youtube, but it's still blazing. I guess it takes a while for my simple mind to stop trippin' over the idea of Bert & Ernie spitting popular gangsta rhymes, but I only dignify it with this kind of attention when it's done well. Believe me, there are quite a few parodies out there of these and other characters on Sesame Street "flowing" over some well known piece of music, but few of them can match this in production value. To paraphrase the maker of this video, someone had a lot of time on his hands.
BTW, a year or two ago there was a video of Bert & Ernie singing "Drop It Like It's Hot" by Pharell Williams and Snoop Dogg, and after a few million hits that disappeared, so there's no telling how long this will last. My advice is to get it out of your system as soon as you find a safe place to watch. Tkae care!