So far, I've found the game looks best using Direct3D and Supereagle.

I haven't tried everything though, anybody have any other suggestions for graphics settings?

Couldn't find a way to get the display centered, but I like these config settings:

output=ddraw
...
aspect=true
scaler=normal3x


I find that a straight resize of the graphics is better. The details are often single-pixel, so any of those filters or blend effects just clobber the image and make it all blurry.

output=direct3d is better, imo...

I tested direct3d with my settings (didn't even know it was an option), and although some effects and items appear shiny the fonts get vertically distorted. The lettering in the main window was especially noticeable.