I don't know if I ever will actually do it (because, let's be honest, putting up and taking down wallpaper is the biggest pain in the you-know-where) but if I were to do it, I would use it as an accent in a room, not as the focal point. I would paper one wall (most likely the smallest wall in the room) and no more. That being said, here are a few patterns I have found that I heart (though I may find such designs to be more desirable for window treatments, etc. but you may disagree) that I will now share with you all.
Vintage II- Duty Leaf
Mirabel Wallcoverings- Tilden
Tree Tops Wallpaper-Birch
Damask Print Wallpaper- Espresso
Damask Print Wallpaper- Charcoal
Leaf Print Wallpaper-Silver
As I said, I probably will never get into the whole wallpaper movement, but never say never. There are a lot of fun and interesting patterns out there that may just be perfect when husband and I have a place of our own. Shrug.