95% of the time, we recommend Google Analytics because the accuracy of the data, the options available for advanced scenarios and its interplay with other Google services are great.
However, there are also plenty of other tools on the market that are just as good or even better. With these, you nevertheless have to consider the cost factor and weigh in whether the price of the additional features is worth it.
From Piwik, another very good free tool, to Kissmetrics to Omniture, we do it all. We are happy to use the tools you are already using or advise you which tool best fits your project. The implementation of professional tools, but most of all the training of your team, involves a certain amount of effort. It is therefore worth taking the selection of your tool seriously.