If one is interested in unbiased reporting then it's probably a good idea to steer well clear of both the Daily Mail and The Guardian. They're both pretty rotten.
Who does provide unbiased reporting? In the UK? I have yet to see a newspaper that is unbiased. In Germany, I am quite sure, we do not have that. But saying the Guardian is as rotten as the Daily Mail seems far fetched to me.
I've no idea. I'm also not sure any news outlet is unbiased. The Guardian relentlessly spins its news in order to be palatable to its rich, middle class and liberal audience. If you're interested in rational, objective reporting then the Guardian is definitely not that ... especially in its cultural/society related opinion pieces. The Guardian is as much skewed to the left as the The Daily Mail is to the right, and once you realise this The Guardian's output can start to look at once absurd and genuinely terrifying. I don't know what the answer is, although I personally try and gather my news from a large range of sources from across the political spectrum in an attempt to gain a heuristic understanding of what might really be going on.
