There are a few respectable ML parties in Europe, though they are usually pretty small. Many of them are anti-EU, which isn’t a bad thing, but idk if that’s what your looking for.
I’ve heard the Belgian communists are pretty strong. Otherwise most of the “communist” organisations tend to be either Trotskyites or Maoists.
Usually you can always find a nice ML organization, it’s only a matter of how small you’re willing to go. Don’t restrain yourself to parties too. Sometimes unions or other political organizations are better. Not being registered as a party can allow for a better ability to express their stances legally, or show their commitment to not participate in bourgeois elections.
Change my mind : Nazis weren’t recruited by NATO and the US despite their war crimes, but thanks to them.