UAE is a famous Amiga emulator ported to the Wii. UAE Wii can be found on googlecode at uae-wii.googlecode.com, and is based on the source code of E-UAE. The port uses SDL Wii.

Changes:

Allow configuring most important options from the menu (Amiga models etc)
Fix Nunchuk/Classic controller conflict
Add virtual keyboard to set keyboard-to-controller-button bindings
Store configuration when modified in the menu and allow uaerc.user to override the configuration
Saving and restoring states now work
Harddisk support is now built in, but works so-so (and has no menu support)
Hundreds of small fixes here and there

http://wiibrew.org/wiki/UAE_Wii