There is an Amiga emulator available for almost ever major system. It started for the UNIX/LINUX systems and progressed. I've tried an MS-DOS version, a Macintosh version, and even an Amiga version (yes, an Amiga emulating an Amiga). I've even had my Amiga emulating a Macintosh emulating an Amiga. The various ports of this emulator are so good that they handle direct writes to the Amiga Chip Set.
If you are interested, click here.
If you really want to use it for something (such as running my Crystal Lattices
program), you need to have a ROM image of the Amiga's kickstart ROM. If you
have an old Amiga, you should be able to get a rom image from it. A 300 MHz Intel type computer can emulate an Amiga faster than the original Amiga (~ 7 MHz).
If you don't have access to a ROM, you can purchase a commercial version of the
emulator with a licensed ROM image included. Do a web search for "Amiga
Forever" to find sources and pricing.