I'm buying new Sony Wega(27") and I need to buy a component video cable to hook up my DVD. Should I get the expensive one (gold-plated) or the regular will do just fine?
Is there a big improvement in terms of a signal?
Thanks.

Gold is there because it does not oxidize and makes for a good connection, nothing more.

IMHO for a screen that size any well made cable will be just fine.

three regular video cables should be fine for you. Just make sure that they are 75 Ohm (which video cables are). Audio cables aren't necessarily, and don't perform as well when you try to put a video signal through them.