Wall decals are such a mixed bag. Some make a room look downright incredible, while others... don't. I'm pretty sure these text/typeface decals from StickHOME/Harmonie-Interieure can do wonders for a wall. These, which are sold in Europe, are highly customizable; you pick the size and color -- and of course, the message.
@ Harmonie-Interieure, 69€ to 129€ (about $100-$200, with shipping)