This question is subjective and it is impossible to definitively answer it i.e Android lovers do not want to hear of other mobile Operating Systems and Windows phone users say that their OS is the best. But both the operating systems are polished and full of features. Still we can compare some of the features of Windows and Android OS. Now lets talk about some features of both the Operating Systems and compare them.
The market is flooded with different models of Android phones. You can choose one according to your need and interest. There are literally dozens of Android smartphones you can buy in the India, and at the last count only five Windows Phone 8 handsets, with a few more now outdated Windows Phone 7.5 phones kicking around the remainder bins in phone shops.
Windows phones require high requirements hence these are high end phones. This doesn't necessarily mean that Android is best, however - the five major Windows Phone 8 smartphones out now are all high-end, high-quality devices built by Nokia, HTC and Samsung to showcase WP8. Those manufacturers rarely make poor hardware.
But Android's high end phones are just superb. Some live examples are Galaxy S3, Galaxy Note 2 and Google's own, LG Nexus 4.
This is another big win for Android. At the last count there were around 700,000 apps for Android on Google Play, the majority of them optimized for smartphones. Two years after launch and Windows Phone is still hovering around the 100,000, most of which were written for Windows 7 (they are forwards compatible with WP8). The bald numbers really don't matter, so long as the key apps are represented, but at the time of writing key big name apps missing from the Windows Phone Apps+Games Store include Spotify, BBC iPlayer, Instagram and games like Bad Piggies and Temple Run. Again Android is the winner. The Windows Phone 8 handsets available are nice, but if you want choice Android is where it is at.
Speed, Stability and Features
This is the area where Windows Phones are better than Android. This is the area where Android's very openness can be both a good and a bad thing. There are a variety of speed, stability and features in the Android world because hardware makers can tweak the software. It is zippy and stable, and has a couple of nice extra features such as Rooms and the brilliant Kids Corner. Windows Phone 8 is fast and friendly.