Which game programming language to use for iOS games.

Hi, I've been doing a lot of research into the different iOS programming languages for iOS games and have found there are quite a few. I've decided to go with an Objective-C type of language for my choice, but have found that in that arena, there's OpenGL ES, Cocos2D, and others.

I'd like to ask which language is recommended for a - beginner - in iOS programming. That said, I know that the best language is the one you know best...but I'd like to pose the question as an opinion question based on your experience with iOS game programming. Please share why you believe that language is the best choice.

Initially, I'm interested in 2D games, which I assume are easier than their 3D counterparts, but I'd like to be able to grow into 3D later on. I'm also interested in learning how a game is put together from end-to-end (i.e. sprites, sprite sheets, texture maps, game loops, physics engines, etc), so I'd like to learn all of that based on the appropriate game development platform.

Thanks,
Fulano