I use Google Analytics and play good. The visits that show Awstats are unique visitors or page impression?

Awstats works off of server logs while Google Analytics is third-party JavaScript (and only counts visitors that have JavaScript enabled by their web browsers). While nearly all web browsers have JavaScript capability, the difference between those who don't and those who do are search engine spiders and other bots which crawl your site.

We also experience some time huge difference during the session, however google analytic result seems more accurate to me, idial approach to use both.

I also find that the google analytic result is less than the server log, it maybe blocked javascript by some user.

I just love Google Analytics pretty accurate results ...

Reason why Google Analytics doesn't show accurate stats is..
1) GA uses JS to track users. and some of your visitors may have it turned off.
2) GA only tracks visitors that have executed the code. So for example: If you have the GA code in footer and a visitor comes to your site and immediately quits or clicks on a ad before the GA code loads. GA doesnt count them.

If you would like to view how much traffic you get you should check your hosting stats like awstats. It's the best tracking tool and far more accurate

Awstats are from server statistics. But Google Analytics is a very reliable source.