ive only had sarah and ive grown fond of girls but i think each has their own set of joys and problems. when ive had the occasion to pick my animals myself ive found they pick me really. id go visit the litter and see which one picks you.
As for picking a pup from a litter, Cesar Milan says to pick the personality that best fits you. More dominant of litter, laid back of litter, energetic, etc.