This is a difficult one, because in my field at least (research science) the trend in Powerpoint presentations is towards plain slides with few bells and whistles. Talks where every slide element whizzes around the screen, there are many colours, and the slide transitions are all dramatic, reduce your ability to get your message across so presentations these days are very "straight."
So one idea might be to deliberately make your presentation look very low-tech. There are plenty of websites where you can create your own personal handwriting font, so you could make the slides using your handwriting and include scans of hand-sketched diagrams and charts. You could create a template so that each slide looks like a page torn from a notebook. If you combine this with a little bit of animation - for instance have a chart's axes appear first, then make the line draw itself across the chart, you could get a wow response as people try to work out how you have managed to animate what do not look anything like traditional Powerpoint elements.
I have made a "page torn out of a notebook" template for my own use (attached) - feel free to use it if you'd like