No such thing as "best" phone. Everyone has different needs and wants. Get what suits you and meets your needs and wants.
I turned off the "best answer" feature on this question because it's JUST too subjective. HOWEVER if I had to pick a "best answer" it would be this one! Nicely said SB!
Obviously here at iMore you are going to find, many, or most saying it's the iPhone. Over at Android Central, it will be one of the many Android phones, etc There IS no right answer, it's what's best for YOU! Some prefer the simple "just works" philosophy of Apple, while others prefer the customization Android phones provide. And these days those lines are blurred further as iOS has become very customizable if you dig a bit, and Androids often have a "simple" mode that can be turned on. And lets not forget Windows Phone. No right answer!
Turn it back on! The answer given by SwitchBeach is spot on...
If it wasn't because it's already dead, the Nokia N900, was a truly smartphone, having USB OTG ten years ago, GPS, manual controls for the camera, PKB, 32GB + MicroSD port, a great OS and more.
I always wanted one of those!
Don't get an iPhone