What are your favorite game development resources for the iPhone? I'll start with cocos2d for the iPhone.
For 3D games, I like Unity
It allows me to code in C#, and make releases for alot of different targets, including iPhone, Windows, Mac, and their proprietary web browser player.
I really like cocos2d. I went from not knowing how to turn on a MacBook to having a multiplayer trivia game working in 5 weeks. Everything is there for a 2d game.
It's worth taking a look at the Airplay SDK - C++ development for iOS (and Android, and a few less significant ARM-based mobile platforms), in Visual Studio.
You can do everything on a Windows PC until the final App Store submission steps, where I believe a Mac is still required.
It's quite impressive. I've only done some basic tests with it so far, but I like what I'm seeing.
The main down-sides appear to be no native debugging on the device (but debugging is available in an emulated ARM build on PC, and in x86 builds), and also the need to use fixed-point math, particularly if drawing anything in 3D (best for performance on cross-platform ARM apps, but does increase development/debugging time somewhat)
I have just made some games with the cannabalt (flixel for iOS) source