I think you need to answer not what appeals to what you want, but what you need; and I come to that conclusion based on your very word choice "plain", "boring",

I think you need to answer not what appeals to what you want, but what you need; and I come to that conclusion based on your very word choice "plain", "boring", "uninteresting". If you need the space, find out what your budget will allow and what meets the accommodations of your team. Solve your problems first, and the rest will follow. 37Signals has been preaching it, and so will I because it works