The first thing most people look for in a video camera is the resolution capability. 1920x1080, 1080p, 1080i, 1280x 720p, HDV, SD, or HD? However, there are at least 4 factors you should be aware of that affect the image quality of video cameras.
If you have the means to a Phantom Flex camera, I highly recommend it. At over 2,000 FPS, you can get some amazing slow motion. If you can't, try this.