All you'll need is an SD card and the following free download.
Want to watch DVDs on your Wii, but don't want to attempt some complicated MacGyver-type hack that messes with your Wii's guts? Try Wondershare Video Converter free, (this is a full trial version, not a demo or 'lite' version) it includes an optimized Wii video format lets you convert DVDs with lossless quality right to your Wii-compatible SD card. Here's a free trial copy and the three short steps you need below:
Free download Video Converter. After a quick install, it will start up automatically and you're set.
Step 1. Convert the DVD files for Wii Console
Put in a DVD, then click "Load DVD", like in the picture below. Keep loading more DVDs if necessary; DVD to Wii Converter lets you convert tons of files at a time with batch conversion.
Step 2: Choose the Wii video format and click convert
After all your files are loaded, select them all by pressing 'Ctrl+A' or 'Command-A' in Mac, then click the "Output Format" drop-down menu like in the picture below and select "Device" > "Game" > "Wii". Then just click the big blue "Convert" button and go make a sandwich or something. Video Converter Ultimate takes several minutes to convert a feature-length DVD because it converts with zero quality loss. When you come back, you'll see your movies have been transformed from DVD to Wii compatible video!
Step 3: Copy the file(s) to your SD Card & Play it!
After conversion is complete, you can copy your new Wii-compatible video file(s) straight to your SD card. When the files are finished copying, just remove the SD card from your computer, stick it in the console, sit back and get ready to enjoy DVD on Wii!
Questions about SD Cards and Wii? Here are Nintendo's SD Card Resources:
Maybe you're having problems playing the converted videos on your SD card, or maybe you don't know which kind of of SD Card you need. Either way, these links should help clear it up--the go straight to Nintendo after all!
Here are Nintendo's SD Card Resources: