Of the two, I prefer winter. I love going for a brisk walk with the snow crunching under my boots and ending up at a favourite hangout for a meal, a draught beer or a glass of wine. Or sitting by my wonderful gas fireplace reading, watching TV or listening to music.
You can choose your destinations on the basis of the season. To be honest, I don't prefer any season over other in terms of trips I plan. Some places show their real beauty in summer while other in winter. That's just how it is.