Colourfullness and Vibrance shaders will help with colour but before touching them try to achieve your desired result with the Tonemap shader. HDR shader will enhance whites and blacks. MXAO is good when it works but it's subtle and resource heavy. Ambient Light can be very effective but requires a lot of tweaking on a case by case basis and is very resource heavy. All depth of field effects except SimpleDOF are resource heavy and tricky to configure. There's a bunch of other filters and effects but many have limited use in live gaming, they're more appropriate for screenshots or just better served by other shaders. Then there's effects like Lumasharpen and Chromatic Aberration which can look great or awful depending on game and configuration.