1964 is one of the top Nintendo 64 Emulators. It runs almost all the Nintendo 64 games at a highly playable rate, and with improved graphics. There are even "Hi-Res" texture packs for many popular games that significantly improve the old titles.
Catching Features is an orienteering game you can play at home. Use it for rainy-day training or rest-day enjoyment. Several different modes of play are available. Individual courses are run with interval starts against computer opponents, or with a mass start against lots of them. Relay events allow you to run one leg of a forked relay course. (from about page)
Console Classix is an online gaming service which "rents" or "loans" ROM images to users when they want to play a certain game. ConsoleClassix has legitimate copies of the games in question, and appears legally able to provide this service because of how the games are distributed. ConsoleClassix utilizes freely distributable emulators for playing the ROMs, most of which are licensed under the GPL.
emu8086 emulates an 8086 microprocessor as well as some peripherals. It includes an IDE with syntax highlighting and a comfortable debugger. Really nice to pick up the basics of assembly programming :-)
Sony PSX Emulator. I know there's a GNU/Linux binary for this emulator, but note the win32 binary launched by wine is AS FAST as the GNU/Linux native version. May be interesting for win32-only ePSXe plugins.
The FreeDO (closed-source) project exists to bring about an emulator or simulator capable of playing content originally made for the now-defunct and no longer commercially available 3DO Interactive Multiplayer, a 32-bit video game console that was licensed to manufacturers and developers, and marketed worldwide in the early to middle 1990s. For more info go there: http://en.wikipedia.org/wiki/3DO_Interactive_Multiplayer
This is a commercial emulator for PC and Mac which emulates the Intellivision game console from the early 80's. It also includes plently of extras, including the history of the Intellivision as well as game art, biographies of the programmers, and video clips.
MAME, the Multiple Arcade Machine Emulator, one of the best emulators around. The most compatible emulator out there, compatible with a vast number of arcade machines form 1975 to 2003. The Plus! Plus! version is a fork with a number of enhancements, such as CPS3 Emulation and Network support through the Kaillera protocol.
MESS (Multiple Emulator Super System) is an emulator for computer systems and game consoles. It strives to be the most accurate emulator for a given system, not the fastest, so it may not perform as well in some areas as other emulators.
NEBULA is an emulator for the hardware found in the CAPCOM CPS2 boards. The games that use this hardware include Super Street Fighter, Street Fighter (Alpha, Zero, Alpha 2, etc), games with Marvel characters and Dungeons & Dragons series.
One of the most complete and accurate emulators for the Famicom/Nintendo Entertainment System. Also emulates Famicom Disk System (FDS) games, as well as Playchoice 10. Based on nester, nesterJ, and UOnester.
One of the best GBA and NDS emulators out there, it's also the smallest one. Just 115Kbytes and you're ready to play! Does NOT requires DirectX, and it's coded in hand-tuned x86 assembler, so it's heavily optimized to run fast even on older machines. It supports savestates, backup RAM, cable link, and even connection with the real console. Now with *partial* NDS support! It is now one of the best DS emulators around, with an accurate 2D core and a 3D core that's becoming more accurate and fast all the time.
PC Atari Emulator is one of the most popular Atari 2600 (VCS) emulators for Windows 9x and MS-DOS. Along with Stella, it is known for supporting the largest number of Atari 2600 titles. Newer Windows versions required having DirectX installed. PCAE for Win9x is written in Delphi (Object Pascal) and x86 assembly language.
SSF is a Sega Saturn emulator for Windows systems using DirectX 9.0c. The current version claims near-complete implementation of the Sega Saturn hardware (not counting emulation bugs), and can emulate the Saturn based Sega Titan Video arcade hardware too.
UltraHLE is the first Nintendo 64 emulator capable of playing commercial games. Said to be a technical demonstration and proof of concept, 1.0 is the only official public release by the original developers.
VICE - The versatile commodore emulator brings old Commodore 64 (and other Commodore computers) programs back into your living room. Play the old games you played many year ago. (Also a native Linux version exists)
Game Boy/Color/Advance Emulator for Windows. It has all the enhanced features you would expect for a modern emulator, such as graphic filters. It supports Direct3D & OpenGL as Graphic APIs, and DirectSound & XAudio2 as Audio APIs. Almost 100% compatibilty with commercial games, it is the best Game Boy emulator for Windows out there.