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). The previous reviewer who said Nestopia can't run full screen stated falsely.
It is THE BEST cycle-exact emulator for NES on OS X. * Support for five additional sound chips. * Transparent decompression of GZIP-compressed game files. * Flexible video display sizes with numerous Blitter effects. * Efficient CPU usage, for improved battery life on PowerBooks. The current version of Nestopia features * Completely free to use.