I have a $20 cable that has plugs for PS2/PS3, Wii, and xbox/360. I was just looking for Wii component cables, but this was cheaper and had a ton more functionality.
See if you can't justify that purchase. Check the no-name cables at Gamestop or somewhere.
Although PS2 games still look bad on my Bravia. Even with pillars on the sides, there seems to be some sort of guesswork being done by my TV to fill in missing rows of image data.
I found that turning off all the programs TVs have that reduce motion blur or whatever make for a better picture.
My friend's PS2 took a shit so he gave me his cable. Much sharper image and color. So far I've only tried DQ8.