The United Kingdom's take on Universal Healthcare, set up in 1945 by the postwar Labour government. The opposition Conservatives (and most doctors) thought it would never work, but by the time the Tories returned to power in 1951, they were forced to admit that the NHS was so popular that they could not dismantle it. It has remained ever since.
The NHS is a pillar of the British establishment, like the monarchy or the BBC - British people love to complain about it, but if any foreigner thinks of doing so in their earshot, they're asking for a punch up the bracket.
Essentially the system works like this: everyone in the UK pays a tax which is then used to contribute to the NHS budget. In return, anyone can receive free healthcare on the NHS at any time, with some provisos - for example, people with chronic illnesses needing regular treatment may have to apply for special programmes. Only certain drugs and operations are available on the NHS, so the organisation walks a delicate balance between “the NHS is using our taxes for frivolous operations!” and “my daughter died because the new drug X wasn't available on the NHS!”
Private healthcare is also available in the UK (notably BUPA) and many richer people prefer to pay for certain things that the NHS traditionally does not do very well, such as dentistry. The advantage of the system is that no-one can get out of paying tax on the NHS, so the rich subsidise the poor's healthcare and everyone gets a bare minimum.
The Conservative party has occasionally tried to tinker with the NHS according to free-market ideology, but has mostly given up after most of these attempts made things worse. For example, Thatcher's government in the 1980s privatised the NHS' hospital cleaners, with the result that poor hospital cleaning is now one of the biggest criticisms of the modern NHS and a cause of hospital superbugs. The current Conservative opposition has limited itself to a pledge to organise things so patients can pick between several hospitals to find the one they prefer - which is basically the same policy they've had for years, but as David Cameron is neither bald nor a vampire, he is likely to be in a position to implement it.
Although the tabloid press like to complain about the NHS, a lot of people are rather proud of it, and it's often cited close to the top of British achievements of the 20th century. One ironic comment about this was “You can take our universal healthcare from our cold, dead hands.”