A is for Army. My three sons' bedrooms all have a different theme, I won't tell you what the other two are yet you will have to wait and see. My middle son has just turned 11 last week and has always been very drawn to all things military (he also looks good in a slouch hat). We had to hand paint all the army fatigue on the walls so it took a bit of time to do but we love the final result. My boys never used the hanging space in their built in cupboards so we took the doors off and put in some down lights, in this room we have put the bed in there.
He has lots of models and memorabilia to much to show it all. Even the fish tank has had the army treatment. The poster we found in a second hand shop he was so excited when we found it.