**EDIT: Please see
this post to view United State of Pop 2011**
So, I realize this is probably a few weeks late, but I figured I'd share it anyway. There's a "DJ" on YouTube who did a mash-up of the Top 25 songs of 2009 according to Billboard, and it's really really good.
He also has one for 2008, which isn't as good:
His 2007 year-end mash-up, however, is again well put-together
So I guess I'd like to use this thread as a place for people to post similar mash-ups or remixes that they like. I'm always really interested to hear how certain songs sound together and what other people can come up with.