i use google analytics and ads free stats! adsfreestats, helps to track ip's better, and analytics i guess is pretty common
I use google analytics as well awstats and webalizer that comes with my hosting. I previously used adfreestats and it was pretty good for a free service.
I also used wealizer because it's in my hosting... hmm?? smarterstats? does it display how do visitors came and when?
I don't like online analytics because they are not designed to meet my requirements. Awstats is great but I'm still in the quest of the approppriate analytics software to run on my own server with full customization.
I use Google Analytics and Webalizer. I also download my log files and run them through various offline parsers. The thing that worries me is that I can never get two programs / stat analysers to agree on anything.