Visual Boy Advance GX is a Game Boy Advance / Game Boy emulator based on VBA-M.

Features:

Wiimote, Nunchuk, Classic, and Gamecube controller support
SRAM and State saving
IPS/UPS/PPF patch support
Custom controller configurations
SD, USB, DVD, SMB, Zip, and 7z support
Compatiblity based on VBA-M r927
MEM2 ROM Storage for fast access
Auto frame skip for those core heavy games
Turbo speed, video zooming, widescreen, and unfiltered video options

Changes:

[2.2.0 – July 22, 2010]
* Fixed broken auto-update

Plenty of legal GBA homebrew games to try out can be found here at PDRoms -> http://www.pdroms.de/files/gameboyadvance/

http://code.google.com/p/vba-wii/