WinUAE is a very feature-rich implementation of an Amiga:
Picasso96 RTG support, so that your Amiga can make use of all available display modes of your PC graphics-card. P96-RTG is implemented as a Zorro-III graphics-card to the Amiga.
CD-ROM drive support, for accessing Amiga CD-ROM discs.
Windows file-system support, so that your Amiga can use your PC hard-drive's file-system directly. Makes it easy to share files between Windows and the Amiga.
Hard-File support, for maximum compatibility, and reduced risk.
Zorro-III memory-expansion support, so that you can emulate up to 256-Megs of RAM inside the Amiga.
Super-Alice custom-chip, with up to 8-Megs of Chip Memory.
Virtual networking support, through either your Ethernet or Dial-Up Networking connection to the world.
MIDI output support.
And many, many more!