iPhone!
According to you, which is the smartest smartphone?
Undoutedly, I-Phone !!!
In my opinion it is the Android Based Smartphones like Samsung Galaxy Note 2 or 3.
Without a single thought - iPhone!!
The smartest based on Android OS is Samsung Galaxy S5 and HTC one (M8) and based on IOS no doubt it`s Iphone
In this hi-tech world we have a wide range of smartphone all are of high configuration. It is not easy to choose a single one from all those. You need to check which is good in cost even after having same configuration, durability and other features. You can not avoid anything of them if you are going to put a single name.
You need to compare first. For example Lenovo K4 Note vs LeEco Le 1s . After the comparison you will come to know which is the best and why it is. At what cost you are looking for the best is a remaining question. So, I don't have single name to put here before knowing the range.
According to me, Samsung s8 is the best SmartPhone. Visit This site for more Feature.