Anisotropic Filtering does very well at 2x, and FSAA set to 4x is perfect. Enablind triple buffering only has a benefit if you have Vsync enabled, which in turn has no effect on the quality of the screenshots, as far as I know. Forcing mipmaps to Trilinear is not needed, as r_texturemode GL_LINEAR_MIMAP_LINEAR in the Tremulous console does the same.