When DS was an infant we fell in love with our video monitor. I think the brand was Summer (?). We must have gone through 5 of them. I remember they worked great in the beginning then the picture would become too grainy or static noise would become unbearable. We would just take it back and get another one.
I'm hoping the quality has improved now but, I'm not so sure after looking at reviews online. Do you have one? Are you happy with yours? What product do you have?