The Dump
- Rated, working ROMs for Neo Geo, Genesis and TurboGrafx-16.
- http://thedump.classicgaming.gamespy.com/

PDRoms
- ROM Images of console and arcade software released to the public domain.
- http://www.pdroms.de/

ENES
- An european dump group whose goal is to save, numerize and immortalize NES games currently out of sight, which are called undumped games.
- http://enes.emunova.net/

Dave's Emu
- Public Domain ROM Images for some systems.
- http://www.davesemu.com

Demo Roms
- A nice collection of Technical Demos (some with source code) for various systems.
- http://www.emucamp.com/demoroms/

RomCenter
- Managing tool for various systems with built-in zip function.
- http://www.romcenter.com/