Give me an AR-15 and an ACOG and I'm good to go. I was never a big fan of the vertical grips, rails, etc.
One??? Give me 10 and I'm better to go ... and to know grips, rails, reflex sights, lights, etc., etc. ... is to love them.
I'm constantly impressed with the "modularity" (is that a word?) of the AR-series rifle/carbine ... it's kinda like the 1911 in the sense that there are so many mods and customizations that the discerning sharpshooter can take on the journey towards finding the "perfect" firearm ...