In the basement of a laundramat, for 3 big reasons:

1. Electric bill - theyre never gonna question how much juice a laundramat uses
2. Smell - Vent your grow room out with the dryer vents. As long as there're 1 or 2 running, it'll cover the smell nicely.
3. Heat - When choppers fly by doing their infra red scans, you're covered.

When I grow up.. I want to own a laundramat.