I loved using Clicktracks. Because it uses log files, one of the major advantages is the ability to apply anything to historical data.
Google analytics to get information about traffic from google and Bing Analytics to get traffic from Bing.
No doubt google analytics is the best tool for analytics as it shows all information about your pages. Whether stat counter just show your traffic details as google analytics shows traffic details , browser details, previous date details , bounce rate etc so just rely on google analytics as compared to stat counter.
Yeah! Google Analytics is best to measure the average time about how many time your visitors spend with your site? From where the visitor came, and he was visiting in your site. For all those strategies Google Analytics is An awesome tool to measure.