What could be more fun that hacking the Wii? Compiling and running your own Wii games is actually pretty straightforward. The only caveat is that you will need a copy of The Legend of Zelda: Twilight Princess and an SD card. For remote debugging, you will also need the USB Gecko. Many people have already written homebrew apps using the open source DevkitPro to compile their stuff.
If you are interesting in hacking the Wii, you need to check out WiiBrew. This is the place to go for information about compiling, running, and debugging your own custom Wii apps. For example, WiiBrew is where I found out about the excellent Homebrew Channel.
Dotbatman is porting the cult classic Super Mario War to the Wii. What are you going to do?
Update: You no longer need a copy of Zelda to install the Homebrew Channel! Check out the latest Bannerbomb hack.
I was GOING to port SMW to Wii, but you got there before me
Any fun ideas on what else I could try porting?
I am sure dotbatman would love your help with the port. Do you have a USB Gecko?