AWstats, it's a bit on the slow side but output detail is great. Just set it to run hourly..
Sawmill, next best thing if it's not better. Has great "click ctreams" user behaviour tracking. Downside is it requires all log files forever. best thing you can do is to compress them but they have to exist.
http://awstats.sourceforge.net/
http://www.sawmill.net/