Where online can I get cheap but GOOD video cables, specifically s-video and composite?

Here's my setup: SNES proprietary s-video cable, NES RCAs, Genesis A/V cable (RCAs), with a plan to get my Genesis modded by OSG with s-video. The SNES cable is admittedly cheap, the Genesis pretty crappy, the NES RCAs are pretty good. These all go into a STEREN A/V switch. I need some decent cables to go from the switchbox to my Dell monitor - s-video and composite video. I bought some from Radio Shack (pic below), but they are cheap crap.

Any recommendations of where to buy good but inexpensive video cables?