Attract-Mode is a GUI for emulators such as MAME, MESS and Nestopia. There is also a mac build of M+GUI that I didn't test. It's working very well on OS X and you can find it here. GUI front ends available on this planet called QMamecat. QMC2 is the successor of one of the first UNIX M.A.M.E. Don't be afraid of Japanese, direct download link for v3.4 is here.

Mame Launcher that You can download from Nekocan site. There are several GUIs for MAME that You can use: You can find more info on OpenEmu homepage and download the latest version from here. There is even older build of MacMAME that You can find on MacMAME homepage. MAME OS X is a native version of MAME with built in GUI but badly outdated. There is frequently updated SDLMame version for Mac OS X. This is considered a nice side effect, and is not MAME's primary focus. Of course, in order to preserve the games and demonstrate that the emulated behavior matches the original, you must also be able to actually play the games. This is done both for educational purposes and for preservation purposes, in order to prevent many historical games from disappearing forever once the hardware they run on stops working. The main purpose of MAME is to be a reference to the inner workings of the emulated arcade machines. The source code to MAME is available for development and learning purposes. MAME can currently emulate several thousand different classic arcade video games from the late 1970s through the modern era. When used in conjunction with images of the original arcade game's ROM and disk data, MAME attempts to reproduce that game as faithfully as possible on a more modern general-purpose computer. MAME stands for Multiple Arcade Machine Emulator.

Mame osx