Hmmm... that's a who's who list of the top phones on the market right now. I wouldn't be unhappy to carry any of them. Gaming of the advanced 3D kind is lacking on Android right now (the 2.0 OS adds 3D support, so that eventually will change). The iPhone is definitely at the top of the gaming heap right now. There are Office suites for each platform as well as streaming music. All will do the things you want. So it may come down to which you like the best in terms of form factor and the one whose user experience was most pleasing.
-------------------- Lisa Gade Editor in Chief, MobileTechReview