Is there any such thing? I don't know of any cloud service provider that offers unlimited bandwidth. There are very few providers who could handle five billion connections per day in the first place, regardless of bandwidth.
popular unmetered options: he.net, ovh, hetzner - You generally lose a lot of the "cloud" capability with these options however.
cloud options: digital ocean egress is $0.01/GB ($0.005/GB if you buy it via droplets), linode is $0.02/GB, vultr is $0.01/GB, etc.
[1] https://www.techempower.com/benchmarks/#section=data-r18&hw=...
10 Gbps fully saturated delivers about 3300TB for that $1-2k/mo, versus the $22k/mo you'd pay AWS for the same.
I'm absolutely not talking about the "unlimited bandwdith" bullshit that discount hosts offer.
[1] https://www.cloudflare.com/case-studies/di-fm-eliminates-egr...