Halo (2001)

The Halo franchise today is intertwined with Xbox, but it wasn't always that way. The series started its life across the platforms, and some will argue that's where it was at its best. The FPS puts you in the body of the Master Chief, an enigmatic warrior defending against an alien race known as The Covenant. They're trying to get hold of a powerful artifact on the ring-shaped planet of Halo, and you must stop them or humankind will face dire consequences. It's a compelling story, made better by excellent sound design and voice acting, as well as some well-polished mechanics. For its time, enemy AI is exceptional, not just running at players but employing more tactical approaches to keep things interesting. That intelligence expands to your comrades on this journey, who will make themselves useful instead of just acting as cannon fodder. However, nothing beats having another person at your side, and it's in multiplayer that Halo really comes into its own. You can play through the entire campaign with a friend, and after that, join online matchmaking. Halo is one of the best-balanced games in the genre, cutting out a lot of noise and progression and adding value through things like weapon pickups and well-designed maps. Even today, you can grab a copy of Halo and play online, giving way to hours and hours of entertainment.