I have been using Sitemeter for years and have it on a number of sites. I much prefer it over Google Analytics as it allows you to track individual visits in real time. I think that if you were getting thousands of visits a day then Google Analytics will come into its own.
Sitemeter on this site is working but one of my sites http://berrycomputers.net.au has frozen back about a week ago. I've sent three requests to them but no answers. I just checked twitter and google and it seems that I am not the only person that has issues with Sitemeter and not the only person not to get a response.
****** UPDATE ******
My stats have started to update once again. Fingers crossed that they are over their issues.