Every Major Fallout 4 Faction, Ranked

screenrant.com:

Throughout the Sole Survivor will come across plenty of character who each will have their own agenda. While some in the Commonwealth might be out for themselves, there are a lot who belong to the various factions who vie for power. As the main questline progresses, the question of which the Sole Survivor should side with in the end will arise, with each faction having its own pros and cons.

There are plenty of groups that can be met in the Commonwealth, with many having great side quests in, and some of the smaller factions have some great characters. While there are far too many to list, some honorable mentions are the synths of Arcadia, who can be met during the DLC, the incredibly cool Atom Cats, and the recently added Enclave. Most of the major factions can be joined, with the possibility of being a member of multiple groups, but which ones are worth the time?

Although the Gunners cannot be joined in their presence in the Commonwealth is significant enough that they can be considered a major faction. The Gunners are a faction that can be encountered in many places across the Commonwealth, and their behavior will change depending on the individual group or circumstances. Based around a pre-war U.S. military structure, the Gunners are a brutal mercenary organization who will accept any contract with no regard for morals. However, despite their military uniforms, strict hierarchy, and combat training, the Gunners are little more than well-dressed raiders.

While some individual Gunners the Sole Survivor may encounter might be peaceful, the majority of Gunners will attack on sight to defend what they see as their territory. Potential companion MacCready is a former member of the Gunners who, when first met, has been having some issues with his former faction. MacCready is a great source of information about the Gunners, as he is most intimately familiar with how they operate. In the Gunners are best known for the Quincy Massacre where they attacked and took over