The Bochs Project
Bochs is a highly portable open source IA-32 (x86) PC emulator.
XePlayer is a best & free Android Emulator for PC that enables all Android games.
KOPLAYER is an Android Emulator which allows you play Android games on PC.
ZSNES is a SNES/Super Famicom emulator for x86 computers.
Xbox 360 Emulator used to emulate games on PC platform.
RPCEmu allows you to emulate classic Acorn systems.
The Device Emulator contains the emulator technologies featured in Windows CE.
Q-emuLator is a software emulator of the QL running in Windows and Mac.
Agat Emulator is an Apple ][ and Agat 7/9 emulator for Windows.
Playstation 2 Emulator by Click-2U is the only all in one emulator.
SoftPerfect Connection Emulator (SCE) is a WAN environment emulator.
Fuse (Free Unix Spectrum Emulator) is, unsurprisingly, a ZX Spectrum emulator.
3DS Emulator is a closed source Nintendo 3DS games emulator for PC.
PS3 Emulator is a free-to-use Play Station 3 emulator.
Consumer QuickSet release for Windows x86/x64 on Inspiron/Studio/StudioXPS.
Donald A. Cupp Jr.
It creates thin and light Linux based images for x86 based PC.