gkAndy says that he can't think of an alternative to today's system. However with
modern technology there is no reason why the entire
population of voting age couldn't be asked to cast a
vote on each item of
legislation. A series of ongoing
referendums (
referenda?), if you like. In fact this is the way that the
Senate of ancient
Rome worked: all
citizens within the city boundaries were entitled to vote on proposed laws.
While this would do away with the problem of elected representatives voting on party lines, rather than according to the wishes of their electorate, it would open up a whole new can of worms. For a start, given the general level of voter apathy, it is unlikely that most people would bother to cast a vote for every item of legislation, especially as most of what goes through Parliaments the world over is mundane day-to-day stuff. This leaves our radical voting system open to abuse and misappropriation by pressure groups and extremist organisations.
Secondly, it still leaves the question of who decides what legislation will be voted upon to start with. Do we have an unelected élite considered responsible enough to draw up these laws on our behalf? Do we leave this down to a single individual, be that monarch, president, prime minister or whatever? Or do we rely on having a system of elected representatives ... in which case we're back to square one.