Google Analytics

I have to say, I really like Google Analytics. It's a free site stats system based on Urchin, which Google bought a while back. It uses Javascript and is unobtrusive in modern browsers. You get really nice, clicky stats. There are a couple problems with it: first and most importantly, it doesn't give you any information on file downloads nor on errors. For that you still need your old-fashioned server logs. The other problem is that everything about it is geared towards sites making money with AdSense. But that's hardly surprising, and after all it's the reason Google can give the service away free: in addition to being useful for site owners, it helps them help Google help them make money. I'm trying it out on several sites for a little over a month now, and I'm very impressed. I just added it here as well - though I was a bit surprised Google hadn't already integrated that into Blogger, which they also own.