I can't see android ever not being the OS of choice for me. a for instance is something that i've literally just discovered. from my mobile i can now control the google music that's playing in the browser on my computer. this is something i can't imagine windows would ever get or for at least a long time. there are too many things i do on android (can windows have customer text tones for each individual contact?) that i'd miss far too much.
On the other hand Xbox music is leagues ahead of Xbox Music on Android and I'm pretty sure you can control it on other devices with it (although MS are very good at releasing good app on other OSs, although the outlook app on Android wasn't brilliant, is was better than the stock android email client, at least with outlook web accounts). It's the same with integration between phone and Xbox console/account.
The integration of different social media and contact details is far superior on WP than android and iOS. It makes swapping between calls, texts, Skype, FB etc so much cleaner than the other two. It's something I really missed on android and now miss on iOS.
On the plus side for Android. It's the only OS that the auto update worked on the Guardian App. I would wake up in the morning with the latest news downloaded to my phone ready for my commute to work. The iOS app is supposed to do that but it doesn't, I have I manually refresh. The WP app didn't even pretend to auto update, although it may do now.
Just use a launcher and a theme then, easy!
That was one of the things that really got me with Android. The disjointed UI. You'd go from the launcher/ theme to a completely different style menu, sometimes with the exact same options as another menu style as the skin "ran out" and you ended up at default Android. It really reminded me of Windows Mobile 6 (not windows phone), although that is in part due to having a WM phone with Touchflo (the precursor to Sense on WM6).
As for recommendations. Depends what you want but at the moment Id recommend:
Lots of apps, games, web browsing and every day useage - iOS
A few apps and some good games, web browsing and every day useage - WP
Customisation and "advanced" features - Android
iOS has all the benefits of Android (except the customisation) but none of the negatives. It also has many of the benefits of WP, but far more apps, and tbh the iPhone 6 is stunning hardware wise, I almost bought the 930 but the lack of apps and the thickness drew me away. The only reason I would recommend Android at the moment is if you want major customisation and/or need in depth apps that do things like sniff wifi, funky VPNs or cameras that record with the screen locked and/or track movement (such as Cerberus)...