I was pro-PR, but recently, looking at italy especially, it just doesn't work. No government EVER gets the majority, and you end up with parties like BNP, UKIP, and god knows what else getting into power because Labour and Conservative need an extra 5-10% to form a winnig coalition.
Equally, first past the post is undemocratic - labour have a majority of 66 seats, so basically, all it takes is for the few hundred thousand (tops) people in the 34 most marginal seats to swing an election.
Obviously, anarchy is a no go (just look at 4chan)
Personally, I'd have a skeletal constitution, guarding freedom of speech, among other things, an elected "supreme court" and a dictator for life. Media influence over politics would be crushed, we could actually get stuff done without reams of re-reading and red tape.
Regards both low turnout and Johnny's "worst government ever" comment, i'd say the reason no-one votes is for the most part (at least at the last election), we're pretty happy. Sure, there was the Iraq war, Cash for honours, Blair vs. Brown, but really, who was directly affected by any of this? Labour stayed in due to mutual dislike for tories, but really, nothing massively radical has happened in politics for years, there's been no need. No matter who you vote for, they're going to tinker at the edges and no more. Turnout will rise when politics begins to affect what they really care about, and that's number one, and more specifically, number one's money.
The credit crisis will see Cameron and co in come 2010, if nothing else.