The one you want to wake up to everyday!

A lot would depend on if you want to brighten up the space or not. If you get a lot of daylight you could probably go with the darker grey. If you want to keep the space light & fresh I would go with the lighter grey color.

i like the first two choices. we had "metropolis" (BM) in our old home - similar to your second choice, and "grey" (a very dark grey) in our bedroom - i prefer metropolis. the grey is very dramatic. the middle shade is a bit more versatile i think.

Use the darker one on one wall and paint the rest of the walls the lighter color.