What aspects do you most look for in a great presentation?

The most important thing is not to make the listener to fall asleep. Passion, emotions, examples everything that can create an entertainment out of presentation is good for it. Once I was playing guitar while presenting creative concepts. Even if you present a small thing you should do it in a way like if it is bigger than life. 

Presentation should be impressive, Points should be shorter and easily undertandable with graphs, images and statistics.

Concise and easy.

To have great presentation - it should be informative, motivating, and inspiring.

I would rank comfort level / confidence of the presenter as most important. Followed by engaging with the audience and good-looking Powerpoint slides with brief bulletpoints or illustrations.

To the point and with full confidence.

Examples, Comparisons, Research statistics, supporting references