I’ve recently switched my stats counting over to Google Analytics instead of just using StatPress, a Plugin for WordPress.
Google Analytics has just about everything you need in terms of statisics and some more as well.
A great benefit with using GA instead of the WordPress plugin is the wide range of iPhone apps that allows you to get access to your stats right on your phone. These apps usually use the GA system and display the stats in a nice iPhone friendly format.
So far, I’m using an app called Analytics App, a paid app that lets you view your stats from anywhere. I’ve yet to use it to the point where I feel that I can give a fair review though!