Well, i´ve got a 27' Plasma, in my father´s house which is like, 5 years old? And looks quite nice (not as nice due to lower brightness level) but certainly looks quite nice with my component cables.
And, my mother has a 49' LCD TV, which along composite cables look, yucky. So I plugged my component cables, and hell it looks beautiful. (Specially in brawl with deflicker Off, looks like every clean object appeared in screen)
For those who don´t know how much component improves signal out put, it makes image more clearly, well defined, and colorful. Ex: Trauma Center Second Opinion is a low res game, which can also be perceived while you play it at CRT TV, so imagine you play it on plasma/LCD TV + Composite cables (A/V ones), it looks awful, pathetic, and everything you might think of.
When you use component cables on those newer P/LCDS, this game improves his polygon definition a lot, it seems beautiful, better "drawn". Obviously, it´s not HD, BUT it really does a fantastic improvement.