Games/emulation

DeSmuME
DeSmuME is a Nintendo DS emulator running homebrew demos and commercial games. You can view a YouTube demo here.

Dolphin
Dolphin is an emulator for two recent Nintendo video game consoles: the GameCube and the Wii. It allows PC gamers to enjoy games for these two consoles in full HD (1080p) with several enhancements: compatibility with all PC controllers, turbo speed, networked multiplayer, and even more! You can view a YouTube demo here.

DOSBox


DOSBox: the famous DOS-emulator that uses the SDL-library. It emulates CPU:286/386 realmode/protected mode, Directory FileSystem/XMS/EMS, Tandy/Hercules/CGA/EGA/VGA/VESA graphics and a SoundBlaster/Gravis Ultra Sound card for excellent sound compatibility with older games. No matter which oldschool dos game you want to play... Dune II, Monkey Island or Syndicate, dosbox runs them all. Also see the compatibility list and the wiki for help. You can view a YouTube demo here.

Higan
Higan (formerly known as bsnes) is a Nintendo multi-system emulator that focuses on accuracy and clean code above all else. It never uses speed or compatibility hacks. As a result, the minimum system requirements are higher than with other emulators. You can view a YouTube demo here.

It currently supports the following systems:


 * Nintendo Entertainment System/Famicom
 * Super Nintendo Entertainment System/Super Famicom
 * Game Boy
 * Game Boy Color
 * Game Boy Advance

Higan also supports the following subsystems:


 * Super Game Boy
 * BS-X Satellaview
 * Sufami Turbo

Mednafen
Mednafen is a command-line driven emulator for many different systems. It has full support for OpenGL and SDL graphics, network play, remappable input configuration, joystick and keyboard support, save states, game rewinding, GSF playback, and screenshots. The systems supported by Mednafen are:


 * Atari Lynx
 * Neo Geo Pocket
 * Neo Geo Pocket Color
 * WonderSwan
 * Game Boy
 * Game Boy Color
 * Game Boy Advance
 * Nintendo Entertainment System/Famicom
 * Super Nintendo Entertainment System/Super Famicom
 * Virtual Boy
 * PC Engine/TurboGrafx 16 (CD)
 * SuperGrafx
 * PC-FX
 * Sega Game Gear
 * Sega Genesis/Megadrive
 * Sega Master System
 * Sony PlayStation

You can view a YouTube demo here

Mupen64Plus


Mupen64Plus is a cross-platform plugin-based fork of the famous Mupen64 Nintendo 64 emulator. Included are four MIPS R4300 CPU emulators, with dynamic recompilers for 32-bit and 64-bit  systems, and necessary plugins for audio, graphical rendering (RDP), signal co-processor (RSP), and input. An OpenGL video plugin is included (called RiceVideo). You can use the gui ( or   USE flag) or use the command line interface (run: ). You can view a YouTube demo here.

PCSX-Reloaded


PCSX-Reloaded is a PlayStation Emulator based on PCSX-df 1.9, with many bugfixes and improvements, which uses a plugin architecture to provide full support for all components of the PSX. It has full emulation support for gamepads, videos, sound, memory cards, and other important PSX components, and is able to play many games without problems. You can view a YouTube demo here.

VBA-M


VBA-M is a fork of VisualBoyAdvance and emulates Game Boy, Game Boy Color, Game Boy Advance, Super Game Boy and Super Game Boy 2. It makes an effort to bring some cohesion to the multiplicity of releases floating around the community and is actively maintained. Examples of games running on VBA-M include Zelda - Link's Awakening, Dragon Ball Advanced and other highlights. You can view a YouTube demo here.

Yabause
Yabause is a Sega Saturn emulator with the following features:


 * Booting games from CD-ROM and ISO files.
 * Booting games with either an emulated or original BIOS.
 * Screenshot support.
 * Save game backups.
 * Cheat system.
 * Fullscreen playing.
 * Multiple debugging options.
 * Joystick support.
 * Region select.

You can view a YouTube demo here.

ZSNES


ZSNES is a Super Nintendo emulator and is known for high compatibility with commercial games. Because it uses x86 assembly it does not use much resources and has decent performance even on old hardware. It's very configurable and runs known games such as Secret of Mana or Final Fantasy 4. You might also want to check out the Top 100 SNES Games list. You can view a YouTube demo here.