HGMServers runs modded Call of Duty servers for IW4x (Modern Warfare 2), Plutonium (Black Ops 2, World at War, Black Ops 1), AlterWare, H2M-Mod and Aurora H1. They stay up 24/7, and the machines are in Europe and North America, so the ping is low wherever you play from.
Play it competitively if that is what you are after: Team Deathmatch, Domination and Free-For-All all run daily. Or play Zombies and find out how many waves you last. Either way your statistics are recorded, the leaderboards move while you play, and the weekly challenges pay credits you can put towards VIP perks without spending anything.
Make an account and it keeps your kills, deaths, K/D, playtime and where you sit across every server. The global leaderboards are worth a look even if you are not chasing the top of them, and most of the talking happens on the Discord.
There is a Minecraft network as well, at play.hgmserve.rs, with Hub, Prison, Skyblock and SMP running on it. Java and Bedrock both work. The section further down has the details.