Aside to Globetrotter: If you use Unix and can install/execute CGI scripts...
I tried paid-for, gazillion-stats scripts like Summary [summary.net
...] and found they provided literally too much data. (Plus server-based updating was a pain.)
So instead I use little Perl scripts that incorporate the 'tail' command and quickly show the last 500 or so lines of my access, error, and mod_rewrite logfiles as web pages I then easily read in any browser. I also use another script that formats the same data by Host/IP, UA, files hit, referrer, etc.
The more complicated script is "Web Activity" by Matt Kruse. (I use an older version.) It's free and also customizable (by hand; do not mess around with scripts if you're new to Perl.) [mattkruse.com
...] I depend on that script. I'd feel blind without it.
(Last but not least, I use Google Webmaster Tools, and Google Analytics.)
For additional ideas, check the other forums here. Lots of people will have lots of info about this, that and the other stats programs.