For the best possible GUILTY GEAR XX ACCENT CORE PLUS R experience first follow this guide to disable the games poor bi-linear filtering at resolutions over 640x480

Please view and read all the screenshots as they are comparing different things. The Dizzy vs May one is the easiest to see the improvements as it is the largest resolution (Click the image again once the page loads for the full resolution)

Tweaked SMAA

Sharpen and Denoise

Increased Colour and Black levels

Optional CRT mode

And of Course..