For me: 1 - Android 2 - iOS 3 - Windows Phone 4 - The "DEAD" Symbian Missing the Meego, and Samsung Bada.
I voted for Windows Phone, the interface and browsing through it goes very easy and smoothly. Also the features from mostly the People Hub is really nice to get to know some status updates. The future for calling will also be very nice with Skype integration coming, sounds like a free call service like WhatsApp.
I already have two Lumia and found WP to be very good and easy. However, I cannot say that it is the best simply because I have never owned an Apple IOS or Android. Certainly my experience with WP7 positively reinforces with long-term positive ownership experience with Nokia.
Absolutely hands down , its Android all the way. I've used all four of these OS's and find Android simple and effective. The A.O.S.P community is going to be hard to beat my friends. So many superior ROM's available .
I believe Symbian will be the best of them all if it still receive the necessary update it should be. To bad Nokia just want to concentrate to Windows Phone now.
Windows Phone is one of best phones, OS. And second is Apple with iOS. Where is Android. Android most terrible devices and OS. If you wanna get it work you have to do a lot of things. It is unstabled, luggy, a lot app crashes. Works like Windows 98, worst than Windows 98. Android is still luggy, doesn't matter you have dual core cpu, quad core or even 8 core cpu. Android developers are really stupid or ....... .
Jolla FTW! I would say that the upcoming sailfish OS will be a true smart OS. If you need more information about it then use this sources: jolla dot com sailfishos dot org wiki.merprojectmerproject dot org maemo dot org Sry because I'm new here I'm not allowed to post normal links but this is not spam just additional Infos.