Varies depending on graphics card configuration. I use the high-end pixel shader combiner with DirectX since all my graphics cards support pixel shaders. Yours may not, so you need to experiment yourself, or leave it on automatic. Texture filters are user preference. If you need framebuffer settings, then either search the board or try them out youself. Other settings you shouldn't really touch.
For audio, use either Jabo's DirectSound 1.6 + RSP or Azimer's HLE Audio WIP2 depending on the game you are running.