I love AWS and for any startup that I expected to need to scale quickly I would choose it in a heartbeat.
However when it comes to low-traffic side projects and experiments where costs of a few hundred dollars matter, I prefer Linode or DigitalOcean with ansible provisioning and B2 for block storage. It will cost you more time for sure, but it will give you better performance at the low-end which means you can break even sooner. If it takes off you can always migrate to AWS, GCP or Azure later.
GCloud recently updated their free-tier (https://cloud.google.com/free/). They provide $300 credit which can be used for any product in GCP, and some services when used within quota are always free. So you might want to give GCP a try for your low-traffic side projects.
However when it comes to low-traffic side projects and experiments where costs of a few hundred dollars matter, I prefer Linode or DigitalOcean with ansible provisioning and B2 for block storage. It will cost you more time for sure, but it will give you better performance at the low-end which means you can break even sooner. If it takes off you can always migrate to AWS, GCP or Azure later.