Mesen is a NES/Famicom emulator and NSF player. It is still a work in progress - some features are currently incomplete or may change in future versions.

Mesen Features:
* High Accuracy - A lot of effort has gone into making Mesen as accurate as possible
* Stand-alone - Put the Mesen application into any folder and run it from there
* Supports: Save States, Movie/Audio Recording, Screenshots, Cheat Codes
* Supported Mapper List (130+): 0 to 13, 15 to 19, 21 to 27, 32 to 34, 37, 38, 44, 45, 47, 49, 52, 57, 58, 60 to 62, 64 to 80, 82, 85 to 89, 91 to 95, 97, 99, 101, 107, 112, 113, 115, 118, 119, 137 to 141, 143 to 157, 159, 163, 164, 176, 180, 184, 185, 189, 191 to 195, 200 to 203, 205 to 207, 210, 218, 225 to 228, 230 to 232, 240 to 243, 246
* NES and Famicom (including Famicom Disk System) support. Also supports: NSF, NSFe, VS System
* Net Play - Play online with friends
* Automatic updates - Mesen is able to check for updates and automatically install new versions of itself.
* Built-in Debugger
* Other Features: 7z/zip archive support, numerous video filters (xBRZ, Scale2x, NTSC, etc.), sound recorder, sound effects, etc.

Mesen v0.9.2 Changelog:

New Features
* UI: Added an initial setup dialog for new users.
* UI: Ability to configure paths and portable mode in preferences.
* HD Packs: New features, bug fixes and audio replacement support.
* Input: Added support for the Famicom's second controller's microphone.
* Savestates: Added ability to save/load the state to/from any file.
* Debugger: Added Lua scripting.
* Debugger: Assembler now has syntax highlighting.
* Debugger: Integration with ASM6 via freem's fork (ASM6f) to import labels and code comments.
* Debugger: Added iNES header editor
* Debugger: PPU viewer enhancements
* Debugger: Added "Developer mode" option for quicker access to debugging tools
* NSF: Added repeat and shuffle options
* General: Improved emulator startup performance
Bug Fixes
* UI: Fixed window size not being remembered correctly in some cases
* FDS: Bug fixes related to cheats and save data
* Debugger: Fixed watch window usability issues and assembler bugs
For: Windows

https://www.mesen.ca