A very dark theme, based in black and green, Automatic Midnight has some nice features including its tabbed comment system.
I designed Automatic Midnight to be a simple, flowing layout that was very minimal in color while showing nice contrast. It features a nice little tabbed comment system, is xhtml 1.0 Transitional compliant, css 2.0 compliant, and tableless. Itís a little different than most WordPress themes as it adds some statistics such as post count, comment count, and lists the posts with most comments down the side.
Check it out at http://www.jcontonio.com/wpthemes