Which Mobile OS is the Best? [- part 1 -]

in the past we had limited choice regarding mobile and mobility solutions , but nowadays we have so many options that we are confused which to choose

here is the laydown:

-Symbian

-Windows Mobile (or Windows Phones)

-IPhone 

-Androide

-WebOs

-Blackberry

and all of them come in different devices, some are full on features, and everyone of them is capable enough

so the real question is Which to choose?