The Super Nintendo Entertainment System (also known as the Super NES, SNES or Super Nintendo) is a 16-bit home video game console developed by Nintendo. The console introduced advanced graphics and sound capabilities compared with other consoles at the time. Additionally, development of a variety of enhancement chips (which were integrated on game circuit boards) helped to keep it competitive in the marketplace.

BSNES has a somewhat different purpose to most emulators; it focuses on accuracy over performance. To that end, it does not include any game specific hacks, or idle-loop skipping optimizations commonly found in other emulators. To add to the fun, it uses a cycle accurate hardware emulation. The net result of all this is the highest system requirements of any software I've released to date; those without an Intel-based Mac need not apply. If you meet the requirements, however, this is the most accurate SNES emulation available on the Macintosh platform. Download from Richard Bannister's site.

SNES9x is older emulator that has problems on recent OS X versions but You can still open roms if You set them to open with SNES9x and double-click. Latest version that I found is v1.53 that can be downloaded from Softpedia page.

OpenEmu also emulates SNES. You can find more info on OpenEmu homepage and download the latest version from here.