You'd be hard-pressed to find a game today that doesn't have some form of multiplayer.
It's become such a normality, games that should otherwise be single-player focused end up getting such a mode shoehorned in for the sake of maintaining interest after an initial launch window. A fully online, 'competitive multiplayer' component was even thrown into Resident Evil with the godawful Umbrella Corps, for crying out loud.
With all these options, it's inevitable that some multiplayer modes are going to pass by under your radar. Many of the following entries on this list even come from the primitive days of online console gaming, and before that, back in the PlayStation 2 and Xbox days when not everyone had their console connected to the internet.
In a world that's so dominated by FPS' like Call of Duty, Battlefield and Overwatch, it's hard to see anything past that. But some games throw a wrench in the basic formula, and just that little bit of something different can really work.
These games deserved more credit and a wider audience, thanks in part to their unique modes, style and addictive gameplay. As good as they may have been, one thing is for sure, they didn't go down in history - but that doesn't mean you shouldn't still check them out.