What I didn't like was how Devin stops by, tells you to choose, and then suddenly you're locked into making up your mind. I figured the choice would come later after a few more missions. Anybody else feel that way?
I didn't want Franklin to kill Michael for Devin because:
1) Michael got him out of the hood, basically, and was always nice to him.
2) Devin is a jerk that didn't pay Franklin and his friends for boosting those cars.
3) Devin tried to kill Michael's family, but I can't remember if Michael told Franklin about it.
I didn't want Franklin to kill Trevor for the Feds because:
1) Despite that confrontation at his aunt's house, Trevor never acted out of line with Franklin.
Trevor is sensitive, and Franklin realized that laughing at him for falling down was wrong.
2) Trevor has been working with Franklin on the heists. They have a work relationship, at least.
Trevor also suspected the drywall drug brick, stopping Franklin & Lamar from being swindled.
3) If Franklin does this job for the Feds, what stops them from telling Franklin to do another job?
So, I chose "C" because Franklin has that hood mentality and would say "come at me bro." I was very happy with the "Godfather"-like ending. I sniped Steve like JFK from the rooftop by the ferris wheel. Interviewer freaked out! I walked up on Stretch and his Balla buddies with Michael, shot Stretch with the silenced pistol and finished the others after they pulled their guns out. Used the automatic pistol on the Triads with Franklin, and then I took out Devin. I was happy that the game let you kill them all, rather than have the other 2 characters do it for you while you do your hit.