Nintendo Entertainment System
The Nintendo Entertainment System (often abbreviated as the NES, also known as the Family Computer or the Famicom in Japan) is an 8-bit home console manufactured by Nintendo. It was launched in 1983 in Japan and 1985 in the US. The NES and counting the various Famiclones such as the Dendy, Pegasus or the Micro Genius in areas where the NES or the Famicom were not sold is considered one of the most recognizable consoles in the world, for many their first console to play games. Nearly everywhere though because in the UK it was a flop thanks to a different gaming market. In Japan it along with the MSX started a video game industry and was the first console there not to be discontinued quickly and in the US, it contributed reviving interests in video games after the North American Video Game Crash.
Ripping
Tile viewers such as YY-CHR and Tile Molester can be used to rip from the ROM. Most NES games can be tile ripped without an issue (apart from assembly due to tile reuse and possible unused poses) aside form games with compressed graphics (such as games converted to cartridges from Famicom disks). Palettes must be manually defined if tiles are ripped and extracted through this manner.
Suggested Emulators
NEStopia
A common, easy to use emulator with save state and quick screenshot support. By default, the system has a rather faded color palette overall, which matches the output of NES and Famicom titles on most modern displays. It can run nearly every NES and Famicom Disk System game with few, if any, real issues, and only lacks support for unlicensed multicasts. Lastly, It can record videos and audio and has net play for online multiplayer.
The Mac OS X version includes a rewind functionality rare on emulators and omits various third-party controllers supportd in the Windows version, featuring only the Zapper for light gun games.
FCEUX
Another easy to use emulator with most of the same features as NEStopia, but with the noteworthy addition of frame-advancing using the emulator's pause function. It's color palette features much more contrast compared to that of NEStopia, making colors much brighter overall. Two features useful for sprite-ripping include the PPU viewer and the Name Table viewer, which display the current tiles loaded into the system's memory for display on the screen and the background without any sprites respectfully. These must be captured using the computer's Printscreen function, as they cannot be saved directly as image files). Like NEStopia, it has video and audio recording and net play for multiplayer.
Mesen
Mesen is a modern emulator that focuses on accuracy, even options to emulate the faults or the variations of the NES but still very easy to use. It can emulate most of the library apart from one mapper that was used in 6 games including Somari and Kart Fighter. For sprite ripping, it includes a tile viewer, sprite viewer, palette viewer and a background viewer. It can record videos and audio, has net play, and can run HD packs for improved visuals.