I'm looking into some powerful hit tracking code. It will need to keep day/wk/month/yr records, individuals behavior, and what files/pages are being viewed and sortable. Lastly I'd prefer it to be PHP. Does anyone have suggestions?

Do you host your website with a hosting company?? If yes, most companies offer tools to track your traffic.
You won't have to install any script.

We are using a hosting company, however it does not fullfill all our needs. One of our sites is an online magazine and I need to have the articles tracked, and they are being used as includes in php. That prevents an accurate representation of what is being viewed

When if you just want to know how many articles are being read, it is very easy to do so.
Whenever an article is pulled, you can just count it. It is very easy to code this with PHP.

you can modify forums script easily to suite your needs. And they give a very good record of hits.

Hoe do tracking codes work? Do they really help keep up with your hits, etc?