Nicely done beatmania + IIDX non-stop megamix. Uses the phrase "QUICK BROWN FOX JUMPS OVER THE LAZY DOG" to pick tracks. One, or several, tracks picked per letter. In four parts because of ewwtube time limitations.
Part 4, in particular, is amazing.http://www.youtube.com/watch?v=lhIZkvN-u1M
Also, it seems the uploader has other megamixes from IIDX and other bemani games.
I just wish I could get the mp3 of this megamix! Maybe he'd toss it my way, though I am not even sure if he is the actual content creator since the video originates from niconico.