The best stats program i've ever used was
Urchin. They did a damn good job with their product.
Looking at their site now, i just noticed that Google ate [aquired] them .. odd.
Anyways.. Unfortunately it's not a free program by nature, but i'll show you how to get it for free. [sort of]
If you pick a host from their
list of recommended hosts, there's a good chance that they offer their clients Urchin web stats for free. [But sometimes they still perm you with an extra fee.
]
Also i'm sure there are many other hosts out there that provide their clients with Urchin, just look around next time you're in the market for a new web host. Some hosts are desperate for clients, if you mention you need it, they may even buy it for you if you move your sites to their servers.
I couldn't find an online demo but they have a free trial, you could possibly try.
Hope this helps,
Josh