Your presentation should be on a subject you have a genuine interest in. There will be a number of these tips that relate back to picking your subject for a presentation, but for now I will focus on this specific aspect.
Enthusiasm goes a very long way when you are presenting. When you are genuinely interested in a subject it draws people in. It is very hard to “appear” enthusiastic about something you have no interest in! It is even harder to maintain enthusiasm when you are presenting the same session multiple times. There has to be something there that gives you that spark, which the others around you can feed off.
When I look around at all the great speakers I’ve met and tried to learn from, they are all really into their subject. They are all speaking about something they feel passionate about. To do anything less than that is cheating yourself and the audience.