This is the simplest hit counter I could imagine (well, almost). Every time a 
page is requested, it adds one to the count. The display is not an image, just 
text. There is no javascript to hit some third-party server, no tracking, no 
distinction among pages: just an old-fashioned site counter CGI, implemented in 
WordPress. The plugin stores its count in its own MySQL table.
Once the plugin is installed (described below), you can display the count by 
putting code like this somewhere on your page:
<pre><code><?= simplehitcounter_hit(); ?>
</code></pre>
That will both increment the counter and display its value. There is no method 
for getting the value without incrementing it. I suppose I could write such a 
thing if anyone likes.
There is a minor race condition. First the plugin updates the database by one 
(atomically), then it queries for the current count. Therefore in heavy traffic 
it is possible for two updates to happen before either select. In that case, 
the counter will correctly increment, but the number displayed may be the same 
for each user, representing the total page hits. As far as I can tell, this 
race condition is inevitable without locking the table. It seems trivial 
enough, though I guess you should be warned if you run a contest to give away a 
free car to the 1,000,000th user.
By default the plugin keeps its data in a table called <code>wp_simplehitcounter_hits</code>. 
You can change this by editing the <code>simplehitcounter.php</code> file.

Simple Hit Counter

Prints a count of the number of hits your blog has received, tracked in the 
database.

Justin Tadlock

Entry Views keeps track of the number of views a post/page (or any post type) has. It comes handy with a widget for showing the most viewed posts, a shortcode for displaying a post’s view count, and handy template tags for use within theme template files.
<h3>Professional Support</h3>
If you need professional plugin support from me, the plugin author, you can access the support forums at <a href="http://themehybrid.com/support" rel="nofollow ugc">Theme Hybrid</a>, which is a professional WordPress help/support site where I handle support for all my plugins and themes for a community of 40,000+ users (and growing).
<h3>Plugin Development</h3>
If you’re a plugin author or just a code hobbyist, you can follow the development of this plugin on it’s <a href="https://github.com/justintadlock/entry-views" rel="nofollow ugc">GitHub repository</a>.
<h3>Donations</h3>
Yes, I do accept donations. If you want to buy me a beer or whatever, you can do so from my <a href="http://themehybrid.com/donate" rel="nofollow ugc">donations page</a>. I appreciate all donations, no matter the size. Further development of this plugin is not contingent on donations, but they are always a nice incentive.

Entry Views

A WordPress plugin for tracking post/page view statistics.

Simple Hit Counter vs Entry Views