I typically do a search every 30 or so days for new projects for better stats. I currently (still) use AWStats (and JAWStats as I mentioned in another thread).
One of the best things about AWStats when compared to it counterparts is ability to break up your datafiles to create reports by day, week, month, year or even hour using the databasebreak feature.
Why people are still using Webalizer and Analog (well, speed aside) is beyond me. At least in my experience they tend to bury as much information as they expose and I end up reading raw logs.