What's your favorite vps hoster?
I'm currently using scaleway and love it, but recently learned that they offer no protection against data loss.
So I'm looking for an alternative for a project in production that has automatic backups as well as unmetered bandwidth.

Why do you need unmetered?
Best ones I have found is Vultr and Upcloud

Unmetered is not strictly required, but for example vultr has not really that much bandwidth.
My project will be serving images. If the average user looks at 50 images per day with an image size of 1 MB, I couldn't serve more than about 650 clients on the 5$ vps - with the rest of the specs being fine. Going up the tiers, bandwidth scales really badly - the 80$ machine only having 5 times the bandwidth.

Im running my servers on azure, digital oceans and host europe.
Also heared good things about Hetzer.

Using time4vps, syncing once a day

Definitely digitalocean! I love the support, the droplets are fairly cheap and the API is great!

Using OVH with unlimited bandwidth

My Fav is server4you, really good cost-benefit ration.