I would go with iPhone 3GS, because this is the perfect consumer phone or if you are a geek and you would like play with it or develop for it then go with an Android phone like the Nexus One or the Droid.

In my opinion the iPhone 3G is your best buy as the software is robust, has great interoperability between other Apple Products, and you have the App store. It's a iPod + phone. It all depends though on what you want. Android is a open-source, which allows for open development, and has little to no restrictions, unlike the iPhone. If your not a hacker, then maybe the iphone is your best choice, as you really have all you need, and its a great product; game changer. Notice how I did not mentioned the Blackberry Storm :)