If your using cpanel then you’ll already have some good stat programs which you can use to monitor your traffic, most notably awstats and webalizer.
Stat programs rarely seem to agree with each other which is why i like to use 1 or 2 more stat programs to give me a more balanced and realistic impression of what traffic to my site is really like. Im particularly a big fan of seeing where referrals are coming from ie. what sites and what search engines.
One of the programs i have started using on my blogs is SlimStat. It isnt anything spectacular but its free, its easy to set up and it provides some useful info about where your traffic is coming from.
You can download SlimStat here
I like that big summary screen where you can see daily, weekly, monthly hits. Also browser and OS platforms, etc all on 1 screen. I'll have to check out this program.
I like to use google analytics (GA) on my websites. Doesn't report traffic in real-time, but does allow you to look at the data in different ways.
Really I also like to see from where my traffic is coming from, and i m going to be delighted when i found i am getting good hits from referals and this shows how much people would like to click on my website, still i am getting currently 30% referal traffic and 45% through SE's. And i also monitor my traffic details through statcounter as well as analytics.
What i feel is traffic really important, i never care about from where i am getting it, infact i really love good and healthy traffic to my site directly coming. Because it shows how much the popular my site is. and people really knows it, and can really easily remember website url and type directly in browser and visit my website.