This is going to be one of those 15 page threads, you should start be identifying you needs for the guys on the forum. What are you going to use it for, hunting, range, home defense, tactical courses, end of the world? What do you see yourself primarily using it for, then what do you see you secondary needs as. Home defense and hunting will get you very different weapons. Identify you price range as well for a total setup, that way you can plan for other expenses, mags, optics, slings, ammo, and all the other parts to make the weapon fit you needs. Buy the gun for your primary purpose, which may be urban home defense, than you can plan out what you would need to use it for hunting.
Remember:
Primary function. Secondary function. Your budget.