PowerPoint is still the tool #1 used for investors pitch decks, just because everybody has the software to edit it. But you should definitely hire a professional designer for the layout and design. We run Unicorn Pitch ( https://unicornpitch.com ), a custom-design service tailored to the needs of investors pitch decks at very affordable prices.

I usually design the first version in Illustrator until overall messaging and brand are on point. Then I convert to a Keynote template or hire someone to cause that shit ain't fun.

Keynote. Spend a day with it and it'll make sense. Most of the same theories of in design apply to it - like master pages

I do two versions. The first is using a neat framework called reveal.js http://lab.hakim.se/reveal-js/ , and the second is a PowerPoint version (unfortunately).

A well put-together Presentation is a leap towards success as it gives you a head start over the other competitors. Get that edge over every other competitor and become the instant favourite before you even start speaking. https://www.designpitchdeck.com/

From our experience it's pretty easy to edit a well designed keynote template by our customers if the template has many different content variations. We tested in on our Pitch Deck Template. (https://pitchdeck.improvepresentation.com)

Thanks for all of the responses everyone! It sounds like Keynote is a pretty strong option. I haven't spent too much time in it. I've heard good things though so I'll definitely check it out.

Keynote is as painful to use as most but the animations are excellent.