I’ve had an iPhone for a while now and I absolutely love it! I can’t imagine owning another phone. So I would definitely suggest getting an iPhone.
One major advantage that the iPhone has over other phones is the iTunes App Store where you can get a whole slew of useful (and not so useful) applications to extend the functionality of your phone. Also, the web browsing experience can’t be beat—it is a true web browser so your experience will be exactly the same as if you were browsing a site on your computer (the exception to this would be that the iPhone doesn’t do Flash).
The downsides to the iPhone are that it doesn’t (yet) do MMS, which I find to be really annoying, but I think this is something they will address in future software updates (which are free). The other downside is that the camera on the iPhone is not great, but it doesn’t stop me from using it all the time—I just wish it was better.
It is possible to switch your number from Verizon to AT&T. You can check to see if your number is eligible for transfer on their website.