edgbla's Software Rendering Plugin is a very accurate Graphics plugin with many features and settings. Compatibility appears to be quite high from the few games I tested.
Plugin requires GTK+ runtime. It can be downloaded here.
* Interlace mode emulation
* Screen settings emulation
* Final Fantasy 8 pre battle effect emulation
* Pixel perfect geometry (I hope. :))
* Method of reducing vertex jittering (pcsxr)
* 16/32-bit software renderer
* Increased internal resolution
* Texture bilinear filtering
* Support for gpuPeteOGL2 glsl shaders
* Fullscreen filters
* High precision GPU commands emulation
* Correct polygon cutting
* Precise dithering
* Correct aspect ratio
* Controlling the plugin with keyboard/mice/joystics
* 9 lightgun crosshairs
* Screenshot creation, video recording