I was adamant from the moment I learned that you had to pick a faction in this game that I wouldn't do that. In the end, I chose the Commonwealth's above-ground groups (BoS, Railroad, Minutemen) over the Institute, because the story arc forces you to at least destroy them to make the other 3 groups happy. I went in & destroyed the Institute with the Minutemen, who seem to be a middle ground/acceptable bunch to team up with for the other two factions.
Before I got there, however, I started following the online guide to the 5th happy ending (the one where the BoS, Minutemen, and Railroad don't turn on each other), but stopped mid-way and began taking quests from all of them, stopping just shy of picking a side or taking a quest I'd read would force me to do so. Then, I went and destroyed the Institute. At that point, I was an active high-ranking member of the Railroad, the General of the Minutemen, and a Paladin for the BoS (having completed the Danse quest by keeping him alive and getting him to agree to remain in the Commonwealth as my companion).
What I've found is so long as you don't activate those 'pick us against them' post-Institute quests (so, you'll never be the leader of the Railroad, or a Sentinel of the BoS, or get Liberty Prime to actually run around even if you do repair it), the 3 factions get along just fine in the aftermath of the Nuclear Option quest and your affinity with them actually goes up, not down. In fact, all of them laud you for destroying the Institute (although the BoS DOES have a rather annoying snit about you doing it without them, and how they never thought the Minutemen had that kind of power).
So, is this a 6th ending -- an ending where everyone's tentatively peaceful, although they all fear hostilities may break out at any time?
If so, perhaps Bethesda might consider creating a DLC where it's possible to bring the remaining groups (including rogue coursers who have decided to give up their Institute loyalty, rogue Raiders who have decided to give up the lifestyle -- like that one Raider who is talking over the grave of his dead buddy, Gunners, and even Super Mutants who agree to undergo Virgil's FEV serum option to revert them) to the table to hash out their differences, so you can...you know...actually rebuild the Commonwealth through compromise. I realize this means eliminating or changing the mind of Maxson somehow, since he's the most fanatical synth hater in the game and is adamant about not tolerating them, but it could work, I think.
What do you think? Would this be a DLC you'd be interested in playing?