I have installed Google analytics on my website for over 2 months and the accuracy of the hit count is rather disturbing. This is how I came to this conlusion:

My website is DotNetNuke that has been opened such that when a visitor hits my site for the first time, a new portal is created – http://www.iflaker.com. On subsequent visits, the portal loads the same site as before using cookies for 30 days. This implies that you can use the number of portals created as the number of unique visits on the site. In other words, if there are 2 000 new portals created in a day, it implies that there were 2 000 unique visits that day. Please note that this is excluding return visits. Google analytics tells me that my site is doing about 5% – 10% of the new portals created. I am expecting Google analytics to tell me that I am doing more than the portals created since there are return visits. Or is it me who is missing something here?

No, it doesn't. Is there a way of doing that? Also, I have installed MyWebKeepAlice. Do you think this could be the issue as well?

A minor nit-pick.

I don't believe Analytics filters out bots.  I believe that Analytics relies on whatever hits your site to both accept and execute some javascript on the page. 

If a browser, with JS enabled, hits the site then the JS advises a Google application which records the hit.  Most bots (maybe all) simply toss away the JS and so never make the call to the Google app.  This has much the same effect as you might expect if you could filter out bots, but it's not the same approach.