EM ADESPOTON  The current version of Nestopia features

* Completely free to use.

* Efficient CPU usage, for improved battery life on PowerBooks.

* Flexible video display sizes with numerous Blitter effects.

* Sound recording functionality.

* Transparent decompression of GZIP-compressed game files.

* Support for 174 different mappers.

* Support for five additional sound chips.

It is THE BEST cycle-exact emulator for NES on OS X.

The previous reviewer who said Nestopia can't run full screen stated falsely. The free version of Nestopia cannot run full-screen; with the purchase of Emulator Enhancer (which works with ALL of Bannister's 28 current emulators).

From his web site:

Additional Features

This feature set above can be expanded using Emulator Enhancer, a shareware module which adds the following additional options:

* Full screen mode.

* Network play (some emulators).

* Real time video and sound filtering.

* Support for USB game pads and joysticks.

EE is currently available for . If anyone wants to rate EE (based on the customer having to pay for it), this belongs in a review of that software, not Nestopia.

Nestopia even has its own support forum now; use it if you need help with the program: http://www.bannister.org/ubb/ultimatebb.php?ubb=forum;f=36

I rated the Features as low, as Nestopia is missing a few features in the free version -- also, it is currently missing support for zip and 7-zip archives, as well as for Quartz effects and OpenGL overlays.

Everything else, I rated as 5, as there are no other NES emulators that perform as well (on ANY platform) as long as you have a fast enough CPU to run it at full speed.  
(Version 1.2.4)

EMULAUNCH  The best Nes emulator available for the Mac. You need emulator enhancer to make the best of all of Richard's emulators but its a small price to pay for all the hard that one person has done porting so many emulators to the mac.   
(Version 1.2.4)

GRAKNOR  This emulator cannot even play in fullscreen mode, pathetic.  
(Version 1.2.3)

ANONYMOUS  The best NES mac emulator. SO the best. I don't like NES much but I play it now just because this emulator is better than my N64 one!!!!

Get this emulator, and get commercial ROMs for it with Limewire a free program that lets you download files  
(Version 1.2)

IAN LUECK  Nestopia 1.2 is FAR faster than previous versions (up to 50% faster, in fact). Anyone who was severely disappointed with Nestopia's former performance (or irritated with how slow RockNES has become) should definitely give the new Nestopia a try.  
(Version 1.2)

ANONYMOUS  Works great....except has no USBcontroller option, the supplied emulator enhancer DOES NOT WORK, all other NES emulators work with USB controllers  
(Version 1.1.2)

RENTED MULE  Best NES emulator on the Mac, period. Sure it's a little slow on older G4s but that's only because the emulator is cycle-accurate and not taking shortcuts like most NES emulators do. Small price to pay for near-perfect emulation, IMO.  
(Version 1.1.2)