Decking Verticle or Horizontal to the house?

Im getting some decking installed of the back of the house cant decide if it should run length ways or long ways against the house. What do people think is the best look?
hmm, while vertical decking is very space efficient, it really should be horizontal :)

More seriously, all deck slats I've seen are parallel, not perpendicular to the house.
Yes, agree with the others. If you run them parallel to the house you make the deck look visually 'longer' and 'narrower'. If you run perpendicular you make it visually 'shorter' and 'wider'.
I'd go horizontal.....vertical could be a bit hard to walk on unless you are in abseiling gear, let alone trying to keep your beer in the glass.
generally most carpenters and builders run the bearers across the longest span as this saves a heap of timber (and maximises their profit;)) hence your decking will run this same direction as well