I'm one of the contributors to Mamesaver, a Windows-based MAME screensaver which plays random MAME games at at specified intervals. We're super excited to announce the release of version 2.0 which, apart from a few licks of paint and a bunch of bug fixes, introduces multi-monitor support, hotkeys, in-game information, customisable fonts, better power management, and better game management.
I run Mamesaver at work and it's a fantastic distraction and really fun to show off games that might have been forgotten.
Mamesaver can be downloaded here, or you can build it yourself. Mamesaver is open source and released under the MIT Licence.
Feature requests, pull requests and bug reports are always welcome!