WordPress MU

What is the most popular stats plugin for WPMU installations? Maybe one that is also fairly light/heavy to the database connections ....

What do you use?

http://firestats.cc/

We use Google Analytics on most of our sites where we're using a specific theme for a specific site.

This obviously means you need to embed some code into the theme template, but that suits us. The reporting you get back from GA is very comprehensive.

Is there any really simple stats plugin for users if just simple information is needed, like unique visitors and incoming links??

Seems like most of all stat plugins I've seen are really heavy with too much info.