I've got a 15m VGA cable running to my projector. It is made from;
15 x 12 core shielded see
here (if you get a cabling diagram you will find that 12 + a shield is sufficient despite it being a 15 pin connector)
2 x 15 pin D see
here
and 2 x backsheels to make it pretty see
here
around $50, perfect quality, run through to smallest of holes (ie only the size of the cable because you put the ends on later), never looked back.
Enjoy.