Two things:

1. Google Lens
2. Kotlin in Android
3. Not to forget, Bubbles game! It was really interesting. ;)

Google Lens looked freakin awesome! Definitely excited about Kotlin, which I didn't know about before, but I'll be looking at it soon for sure. I think the coolest thing was all the hype about AI and the new TPU. All their work into Neural Nets and AI seems really cool.

I loved the improvements made to Google Home, seemed very promising.