PC emulators?

What are some emulators for the pc?

do you mean to run on a pc or to emulate a pc on somthing and if so what

Visual Boy Advance - Gameboy/GBC/GBA
NesterJ or Jnes - NES
ZSNESW - SNES (this one is very basic, but it runs good and no install needed)
Project64/PJ64 - N64
GENS - Sega Genisis
Pcaewin - Atari 2600
Mame32 - "user friendly" arcade emu
ePSXe - PS1