How can I record a TV screen with my camcorder without that annoying onscreen flicker?

Television screens typically refresh at a rate of 60Hz. The reason the flicker appears in your recording is because the television produces an interlaced signal, replacing every other line on the screen, taking two full frames to completely replace the screen image. Under normal circumstances, setting the digital video camera to record at some multiple of 30 frames per second will eliminate the flicker. High end digital video cameras offer manual controls for adjusting the number of frames captured per second, which allows the camera operator to manual adjust the recording speed to match the refresh rate of the television. Consumer camera owners don't have the luxury of manual adjustment. To make things more complicated, consumer DV cameras general turn on some form of image stabilization by default, which causes the camera to record at a frame rate that isn't a multiple of 30. In most cases, turning off image stabilization in the DV camera will eliminate the flicker.