The Android onslaught has made it the most popular smartphone O/S. The recent IDC figures shows a whopping 79.3% market share domination! Leaving the other competing platform in the dust. The nearest contender from Apple IOS only managed a miserably 13.2% market share. And my second favourite Windows Phone platform still has a lot of catching up to do standing at 3.7%.
Google's Android phone is used by Samsung, Sony, LG, Lenovo, Huawei, ZTE, HTC and various others. With the ability for the vendors to customized the Android platform it was the most preferred platform for many of the hardware makers. I even came across some CCTV system using Android as platform based to manage their security CCTV hardware!
Apple with their closed software system makes them less interesting. Although they do manage to create quite a good hardware to go together with their IOS software. Innovation from Apple has not been improving much and they have been resorting to suing Google's vendor to stifle competition, but much to their detriment as the legal counter attack now risk Apple's product from being banned from being imported into the U.S.A. market!
As for Windows Phone, it looked promising especially with the Nokia leading the fray with their innovation on the Windows Platform leading at 81.6% against the other Windows Phone vendor such as Samsung Ativ series and HTC Windows Phone. Still if you want a good Windows Phone, Nokia is the recommended vendor. Windows still got a long way to go as they came in late with a good system. Their previous poorly made Windows Mobile platform turned off many potential users and it would certainly take time to woo new users as well as app developers.
As for Blackberry, they are experiencing market share shrinkage. Though at one time they were very popular at one time, their popularity is now waning. Personally I wouldn't go for Blackberry unless you really need the enhance security and privacy for your emails. Such increased security comes with a price; it means you need to pay extra to your telco for the Blackberry data service. Unless you are working with in the enforcement, governmental department, underground mafia or terrorist, you probably don't really need the extra added security!
Myself having owned a Samsung Note 2, a Nokia Lumia 800 and handling my wife's Apple iPhone 4 and 5, I have a fair idea on each of the good points and bad points of each OS platform. Personally I like the Android OS because it has the most apps and the ability for customization. I liked the Windows Phone for its eye catching Metro style though it still has a long way to go in the app software department. As for Apple IOS, I deemed it the least favourable for me from its simpleton user interface and lack of customization ability and very slow update connection from the Apple server making it a pain to update apps.