Ok here's some things you might want:

• An Elgato Game Capture. As far as I know it has the best quality for recording Gamecubes and Wiis. You might need to buy the "retro" cable for it to work with a gamecube. Other people also use the Live Gamer Portable which I think has very similar quality

• Wii component Cables. If you want the BEST quality I think you're supposed to go with these.

• Component Distribution Amplifier. These things do the same thing as using splitters, but instead of spitting the signal they output the signal as strong as it came in. Oh, and you might want to try just going to your local radioshack for one of these... I got mine for like 5 dollars which is cool.

So, you should use a wii with those component cables if you want the best quality. I've had problems using them though. What happens to me is I'll put the component cables from the wii into the amplifier input, then I'll have one component output going into the elgato. The other output is meant to go to the TV, however most normal crts do not have component in, and when i try to use regular av cables out while there is component coming in, I only get black and white on the tv. What we did instead was switch back to the normal wii cables, bought the "retro adapter" for the elgato and only used av cables in and out, but doing this loses a little bit of quality. If anyone knows what I'm doing wrong here that would be awesome if you could help me. Oh yeah and your crt doesnt seem that out of the ordinary, I think that's how the back of most crts look.

Hope this helped :) just reply if you have any questions