I just want to know, that in the long run, using which of these engines will be better. Although I feel that using Cocos2D will be a better option, as it can also be used for iphone development, there's just 1 tutorial http://dan.clarke.name/2011/04/how-to-make-a-simple-android-game-with-cocos2d/ which I've found so far. libgdx, on the other hand has a complete book.
I will suggest libgdx too. It looks more promising than AndEngine.