Stats program, which one do you use and why?

[cthulhu_waves]

I am planning to write an article for a webmaster portal about statistic programs. I was wondering what webmasters think and which ones are the most popular.

Like what most people use, I always go for Google Analytics. It's been sufficient for my purposes. But I was wondering -- if you could build your dream Stats program, what other program would you use? What functionality? What technology? etc.

Could you please give me your feedback?