This way or that?

I am officially on the count down...I have 3 days left of work before I get 1 wonderful well deserved week off! I cannot wait, I'm pretty sure the rest of the week is going to go by at a snail's pace. I am thinking about redoing The Kid's room. She got some super cute new bedding for Christmas (ok ok... it was the Christmas of 2007, I not on the ball with this I know!) so now I want to repaint her room to match. When we first moved in to our house I painstakingly spent 3 days painting polka-dots on her walls and I am sad to see those go, which is maybe why I have procrastinated so long. Anyways, I am trading dots for stripes. I can't decide on whether to do vertical or horizontal, any suggestions? Here is my one inspiration so far: