There are a number of options available, from a few pound ( well maybe a bit more than a few) up to several hundred. It all depends on what you want to do, and as important you budget. Certainly the rod mike is a good option, they now have about 6 video mics available from about £50 to £170. Big fan of Sennheiser mics, but they do tend to be expensive. One point to bear in mind is that camera amps can be a bit noisy as far as hiss is concerned. ( Especially on 5D's and 6D's ) When using on camera mics I tend to run them through a Zoom H1 as a preamp and send a "hot" signal to the camera so as I can keep the gain low and thus the noise low as well.