Android Jelly Bean any day!! I personally own iPhone 4S and previously had HTC desire, and I miss my Android phone every day I use my iPhone 4S. Thanks to the Jailbreaking community for making the iPhone useable, without it that device is worth nothing.
As far as market is concerned, Android market is growing and I feel bigger then iPhone because of different hardware manufactures. More vendors mean more options for end users. iPhone has not only the same looking UI but also the devices are more or less same.