Some blog and site counter I used for my blogs are sitemeter, histats,
Sitemeter.com have a complete tracking not only counting our visitor,
and it was able to predicting our next visitor.
Histats.com have a excelent flash animated counters, each of them have a
different animation style.
Goingup.com brought to us some plugins for wordpress and blogger, their
tracker could show pop up statistic, not only tracker but also offer
tag cloud, pr checker and many more.