"The Designer's Guide to Startup Weekend," PowerPoint presentation design by Iryna Nezhynska, via Behance. I love the simple colors and flat shapes, with the plays on typography and infographic design.
Business Plan Powerpoint by Design District, via Behance
Persuasive - Keynote Presentation | Keynote theme / template
Thumper - Keynote Presentation Template | Keynote theme / template
The Slide Deck- A Keynote Template | Keynote theme / template