I can't seem to get this game to take up all the screen real estate on my monitor.

I've tried various combinations of options in the graphics utility that comes with it, but the game always shows up as a small little box in the center with a lot of black border... no matter if its original resolution or up to my native rez. Doesn't matter if its fullscreen or in a window... it just is always kinda small.

Any tips on how to get it to fill the screen?

Choose a different video output other than 'surface.'