I'm making a post about an old game, because I'm very surprised to not find any good documentation on this issue on the web.
If you want Resident Evil Archives: RE1 to not look horrible on your HDTV, change your Wii U or Wii system settings to 4:3 (which also means you need to change the resolution to 480p).
Why? Because playing in 16:9 mode will add borders to both sides of the screen, correcting the aspect ratio to 4:3 internally before it is output to your TV. This is a big deal because it means the image you are viewing is much, much less than 480p. The pre-rendered backgrounds don't suffer in quality too much by the dip in resolution, but it is very noticeable on the 3D models. Playing in 4:3 mode on the Wii U/Wii and setting your TV to 4:3 mode also will remove this issue entirely.
Here is a comparison I made. The images were taken by my phone but you can still tell there is a huge difference!
Thankfully Resident Evil Archives: RE0 does not have these issues at all, and displays the full image even when the Wii settings are 16:9.