I think there are many important aspects to make a good photograph but the most important would have to be: interesting and engaging subject matter. Even if certain technical aspects are not well executed such as focus and composition, there can still be a reason for finding the photo meaningful. Ideally, engaging subject matter, lighting, composition and a sharp focal point are the most important aspects, collaboratively. Interesting lighting in photography is most fundamental, composition contributes in giving impact and aesthetic merit, and a part of the photo in good focus to draw our attention to the subject are very important. But an uninteresting subject matter for me will still leave a photo with little appeal even if all the other technical aspects mentioned are well executed.