Site Meters.

Site meters or Hit meters are a must for all web sites. These enable the web masters to find the statistics of their web site visitor's page views, visit durations, visitor's country and many more useful things. This information will allow them to modify their web site according to the visitors pattern, see the expected growth and buy further bandwidth. Also can watch how your advertising is working as most of the site meters give you the details of the incoming and exit page details. You can find site meters in the internet which are available freely and some are available for to buy. New web masters can go with the free ones and can later change them to paid ones.

The tracking meter code (Java or HTML) must be pasted in to your home page as code and uploaded in to your hosting files. You can allow the visitors to see all the details or can restrict them to certain section or hide them all completely.

Google Analytics.
This is the best system which allows you to find about your web sites hits, visitors information and many more things. And it is totally free. All you have to do is create an account with them and get the code
and past it as instructed. After 24 hours you can find all the facts about your web site's traffic.
http://www.google.com/analytics/

Sitemeter.com
This is widely used by web masters all over the world. It is free to use on your website. Very simple to use. Become a member and get the tracking code and paste it in to your source and upload it. You will see
many useful information about your sites visitors information. If you pay the company, you can hide the meter and results from your visitors.
http://www.sitemeter.com

Activemeter.com
This offers a unique web site analyzer which is designed around web visitors to give you accurate web site tracking service. The information are very useful to web masters.
http://www.activemeter.com/

FREE COUNTER & WEB SITE STATISTICS
Site Tracker offers the best Web site statistics analysis of any service around. Site Tracker is much more than a free counter that just tracks your hits; our service leaves an ordinary, free counter in the dust! Track your top referrers, most popular pages, browsers, screen resolution and much, much more.
http://www.sitetracker.com/

http://www.websitetracker.com/
http://www.benchmarktracking.com/
http://www.onestat.com/