BB10 Looks promising, waiting to see if it actually delivers. I really like the gestures, especially the gesture to get to your messages from anywhere. I do hope they turn the company around, it's hard seeing another Canadian Tech company/giant fail, but it is embarrassing/epic failure that it has taken this long to release BB10 or up-to-date hardware while the company remains on life support.
Android/iOS I consider to be on par, for anyone new to the game you can't go wrong with either, the differences are minor, some love/hate things based on preference or their use. I own an iPhone 5 and android tablet, so I've experienced both extensively for 6 months+. I personally prefer iOS and think the initial setup and overall user experience is better and more streamlined (less fragmentation).