We must address the elephant in the room. Downloading a ROM of The Legend of Zelda: Skyward Sword is illegal unless you dump the game yourself from a legally owned disc.
Nintendo actively protects its intellectual property. However, for the sake of the "better" experience, we assume you own a legal copy of the Wii disc (which costs roughly $20-30 used) or the Switch version.
If you own the disc, ripping it to your PC is legal in many jurisdictions (Fair Use/Backup rights). If you do not own the disc, downloading a pre-made ROM is technically software piracy.
How to get a "Legal" ROM:
Assuming you have your legal backup, let's make it "better."
This is the most important section for your search. You don't just want the ROM; you want the Hydrogen HD Texture Pack.
This is a community-made mod that upscales every texture in the game using AI. The difference is night and day. The original "Impressionist painting" art style of the game (intended to hide low resolution) finally shines. zelda skyward sword wii rom download better
To get the "Better" visuals:
Result: You are now playing at 4K with high-definition textures, vibrant watercolors, and crisp text. This is objectively "better" than the Wii U upscaling and arguably rivals the Switch port.
The "Better" Hack: Go to Graphics > Hacks and enable "Immediately Present XFB" and "Store XFB Copies to Texture Only". This removes the input lag from the original Wii’s frame buffer. We must address the elephant in the room
Playing the ROM
To play the ROM, you'll need a Wii emulator or a compatible console. Here are a few options: