[jagrsw]

Probably Switzerland - init7 has it in its offer: https://www.init7.net/en/internet/fiber7/

The price is the same as for 1Gbps and 10Gbps (~60USD/month) - though the initial setup price differs: ~300USD for 25Gb/s vs <100USD for 1Gbps

The actual speed within network is indeed 25Gb/s to some fellow users running speedtest.net servers. Inside Switzerland it's maybe ~15Gb/s to some well connected servers in the area of Zurich, and ~10Gb/s across EU. Tested with speedtest.net and iperf.

[Youden]

I think in the EU the limit is sometimes not Init7 but the Speedtest.net servers. I ran a test to many of them and did get above 10Gbps but only to eu-25g.ookla.tierservers.com, which clearly has a 25Gbps NIC.

A bunch of other Speedtest.net servers were located in Amsterdam and took a very similar route via Cogent but none of the others broke the 10Gbps barrier.

It is for sure often Init7 though. Those peering relationships it built up have become a bit of a weakness because they're usually limited to a 10Gbps port.