My belated Etsy Shop of the Week goes to decal genious PopWall. I'm all about wall decor. As a renter, anything you can do to jazz up those boring white walls is great. Which is one reason why I like decals. Most decals are removable so you can slap 'em on when you move in and pull 'em off when you move out.
The best thing about working with PopWall is that they'll help you customize your decal before you make your purchase. Send them a picture of your room and they'll photoshop the decal of your choice into the picture so you can see what it looks like. You can also pick from a variety of color options and adjust the size if you need a larger/smaller decal. If you don't see a decal that you like, convo PopWall and they'll make a custom decal for you. Who says you can't get good help nowadays!