Google Analytics and similar solutions (client side, only track HTML pages) are really popular these days for analyzing web traffic, but it is obviously not a substitute to logfile analysis.
The two main projects are Webalizer[1], really outdated now, and AWStats[2], which has not evolved for years.
So, what do you use to visualize the logfiles of your webserver?
[1] http://www.webalizer.org/
[2] http://awstats.sourceforge.net/