At the minimum presentations need to address all of the key topics an investor needs to learn about your business.  Just because these topics are generally considered dry (by anyone who is not a tech business nerd, such as myself) doesn't mean that you can't make the presentation more fun for investors to hear.

I have seen a variety of approaches to fun presentations over time, some that use characters or cartoons to tell the stories and others that use gripping pictures to bring concepts to life.  If you can integrate fun elements into your presentations (without being too childish) you may be better off for a few reasons. 

First, fun presentations set the tone of the meeting.  A playful presentation is more likely to facilitate a more lighthearted conversation with the investors.  While this doesn't mean that tough questions won't be asked, it can transform cold poker faces into light-hearted laughing counterparties.

Second, these presentations can be more memorable.  Being memorable is not only important for keeping your business top of mind with overloaded investors, but it can also help them remember key nuances of your business that will help them make the case to their partners.

Investors hear a lot of business ideas each week, if you keep the humor professional and mature, having a little fun with the presentation might help you stand out and get to the next step in the process.