WordPress Hit Counter is a simple plugin that embeds a rotating odometer style hit counter on your blog showing how many visitors your site has.
With Stat Counter Widget you can show to your users how much traffic you have on your wordpress site/blog.
AFS Analytics provides one of the best real-time web analytics tool using the latest technologies. Free!
Animated traffic flash counter .
Visitor Hit Counter plugin. You have the ability to chooce from different stlyles and the option to add it in your sidebar or in the footer.