What can I do to animate 2d graphics, like menu systems on the iphone using untiy?
GUIManager, SpriteUI, SM2 etc. Do a forum search and you will find a ton of options.
Whats the best one?
None are the “best”. They are all very good and useful. Try them out and see which one suits you. I also just released a simple GUI/HUD library yesterday that is very easy to use: