Which one should I choose? BTW I set window res to 1600x900 (my monitor's native res), enabled double buffering, set OpenGL in graphic mode and in DOS settings of SW I chose 800x600. Is this the best I can do right now without source ports?

:(

Venture to here: http://www.gog.com/forum/shadow_warrior_complete/shadow_warrior_complete_with_direct3d_pixelshader_nglide

It should help you. I am bout to update the first post in there to include an url to watch me play it in HD!