Emulator core

use Recompiler instead of Interpreter**
disable the speed limiter (!)
enable Register Caching**
enable Advanced Block Linking**
enable Larger Compiler Buffer**
use less secure method to handle self-modifying code**
don't enable the expansion pack if it's not needed**
state saving and loading sometimes helps the recompiler**
disable TLB (but only if not needed!)** [/list]


Plugins

use Direct3D HAL rather than RGB Emulation or Reference Rasterizer (!)
use the RSP recompiler core rather than interpreter core
don't use any form of Framebuffer emulation
don't enable Sync game to Audio
use a lower resolution
disable "change blending mode..."
enable Display List Culling
use 16 bit colour modes rather than 24/32
if you want true colour, use 32 bit rather than 24*
use Double or Triple Buffering rather than Transfer Memory*
disable RSP audio emulation (and use an HLE capable audio plugin if you want audio!)
use Direct3D T&L HAL rather than Direct3D HAL, or vice-versa*
use External Transforms rather than Internal, or vice-versa*
choose 16bpp textures rather than 16 and 32bpp
don't use anisotropic filtering*
disable fog*


* effectiveness depends on system (hardware)
** effectiveness depends on game