Does upgrading the cables used to hook up home theater systems make a big difference?

I recently bought a new tv a 720p 56" JVC rear projection TV as well as a 5.1 channel Pionner home theater system w/ a dvd player. I'm curious if I upgrade the cables to hook the system up to the TV if that would improve the sound/video quality? If so what cable would be used to do this the TV has the following inputs:

2 S-video (1 side, 1 rear); 2 component video; 3 composite video (1 side, 2 rear); 1 PC; 2 HDMI and 3 audio (1 side, 2 rear)

Also I'm not sure if this would be an issue as i have not tried it yet but I also have a PS3 that i will be hooking up via HDMI to the TV and want to be sure that the surround sound will work when I'm playing games or watching Blue Ray movies. Thanks in advance for your help!!

Does upgrading the cables used to hook up home theater systems make a big difference?

Yes, a quality cable does make a difference, but don't get sucked in by some hundred dollar monster cable.

Does upgrading the cables used to hook up home theater systems make a big difference?opera mobile opera theater

You should use the HDMI cable from your PS3 to the TV (get the lowest cost HDMI cable), but also connect the digital audio output from the PS3 to the Pioneer digital audio inputs (either optical or coax). It is not clear if the TV will output digital audio from its HDMI input; you will have to look in the user manual for the TV to see what the digital audio output from the TV will support. You should also be connecting the digital audio output from the TV to the pioneer, so you can get surround sound from broadcast TV. If the TV passes the digital audio from the HDMI to its digital audio output, then you do not need the optical/coax connection from the PS3 to the Pioneer.
Yes the cables do count and based on your specs I would use the super video or composite hook ups for the TV and the PS# on the HDMI
Yes Big Big difference I use HDMI and Component video
I can tell you that the cables you buy at the store are mostly a rip-off...You should make your own out of "RG6" cable...The RG6 has ZERO signal loss up to 100 feet...So 3 feet between your DVD and TV will be fine...Here's a link to show you how to do it: http://www.whydoesmyhometheatersuck.com/...

And I know that HDMI is the "big bad" cable of the future, but it won't always give you the best connection...There are other things to consider...Click this to see what I'm talking about: http://www.whydoesmyhometheatersuck.com/...

But your JVC can't show a "1080p" signal...That's all HDMI is good for these days...Your TV can only show "720p"...So you might save that $150 on an HDMI cable...Or like we suggested, try it both ways and see for yourself which gives you the SHARPER picture...Here's a link explaining differences in picture quality: http://www.whydoesmyhometheatersuck.com/...

And I can assure you that on our $100 "boom-box" at only 7 watts per channel, RG6 made a TREMENDOUS sound improvement...Think how much more it can do for your Pioneer...But don't take my word for it...Go and try it yourself.