Reinvent is one of those conferences , where even you don't go to the actual conference, you benefit from it because of the sheer amount of content it generates of which most of the sessions are uploaded to youtube. Other than the actual sessions, the social media buzz and discussions around the time of the conference is equally enjoyable and full of insights.
For this past Reinvent. I have made a list of sessions that I want to watch over the next year:
https://www.youtube.com/watch?v=i4Prnei87ao
Migrating to the Cloud with Serverless: What Enterprises Need to Know (DEM04):