The best Downfall mash was this one. Why? Because it perfectly captured the massive Labour wobble about Brown in 2008, when they could have got rid of him. It also reminds us why the Guardian has switched sides today, and regrets reversing the position it took at the time: that Brown should have gone.
Mind you, it's bloody funny too. Be warned, however, that there are tons of swear words, and I usually try to stay away from that kind of language. I bloody do.