Nah, cause zombies never say yes.  You should know that.

Ideas:
- Storage - stick junk there
- Backup room - just in case your main bedroom gets burnt down, you have a backup
- Experimentation room - experiment with different wallpapers before commiting changes to your own room
- Prank room - close the curtains and stick a bubble generator in there, turn it on and close the door, so when someone feels like poking their head in, they get greeted by a million bubbles

Or try the suggestions already given :P