For years during the DVD era, the number one question I'd be asked by friends inquiring about home theater advice was about 16:9 or letterbox formatting. With the mass adoption of HDTV displays, most of these friends now know pan and scan is to be avoided at all costs. But now, the most common question has shifted over to HD video: "Now explain to me why 720p is better than 1080i?".
Benjamin Higginbotham, the Technology Evangelist, does an excellent job of explaining the hierarchy of video resolution in the video below, illustrating visually why you should shoot and watch video in 720p rather than the seemingly numerically superior label of 1080i. Motion artifacting and frame rate are two reasons given, but if you're a newbie to these terms, sometimes just seeing the differences visually can turn on the light bulb upstairs:
So remember this list ranking for screen resolutions whether for shooting HD video or when given an option to choose a video viewing resolution (from best to worst):