I love the winter. It's so much cooler (I overheat badly) and running in the dark means no-one can see my purple sweaty face.
Today is gorgeous here in Inverness - not a cloud in the sky or a breath of wind, the first touch of frost (yes, really) - so crisp and fresh. Weekend days like this are a joy to run on - the leaves turning to their autumn colours, the smell of the trees as you run through the woods, and later, the fresh white snow on the bare branches. Ahhh, loverly.
Good tip - running in deep fresh snow is a brilliant workout - gets the knee lift working well.
Best non-running related winter tip - Don't eat yellow snow......