Mac every time for me. They're better in every single way that matters to me, except for games. But then I suppose that's what games consoles are for.
I've lost count of the amount of time I've spent trying to fix Windows machines with one random problem or another that has left a computer completely unusable, but I've never once had a show stopping problem on a Mac. That's not to say there aren't problems, of course there are but they're a drop in the ocean compared to Window issues.
I also like Linux in principal, and love tinkering around with it and tearing up the command line. But that's the problem with it, there's too much tinkering to be done before it's actually useful. Whereas Macs are useful straight out of the box, my productivity is much higher on a Mac than anything else.
For me that's well worth an extra few £, although that said I think the expense of Macs is vastly over reported, if you compare like for like instead of just the headline figure of CPU and RAM then Macs often come out the same or cheaper that the equivalent Windows machine, particularly when taking into account software as well.