Gov.uk is a great example for any web developer to follow. You can see the thought they've put into ensuring clarity of information, casting aside complicated, whizzy graphics. Also it's very accessible for those with disabilities.
I can only assume that this was one project kept well away from the steer of our politicians!
It's more the fact that it wasn't put out to tender and won by a big outsourcing company like Capita. They would have tried to implement it all using SharePoint, gone massively overbudget and bailed leaving a slow mess that everyone avoids.
Instead, lots of small projects written by a young team using sensible technologies and sticking to an excellent set of user interface guides.
I can only assume that this was one project kept well away from the steer of our politicians!