The minutemen (Friendly BoS) ending is the answer to me.
You keep BoS and RR up and running and get a stream of new post MQ quests.
(Smuggling synths away from the commonwealth,selling reactor coolant to the BoS etc..)
The game feels good since your companions are happy about what you did and you only lose that courser-guy companion.
If you complete the game with the Institure it feels very wierd because you become some kind of entitled-i know whats best for everyone-outcast above ground.
The BoS ending is also cool,being a Sentinel is dope and their are not as bad and extremists as they are made out to be.
Basically the Minutemen ending is similar to the BoS ending but you are giving synths a chance at survival this way (Also quests).