Well going by the title of the post I am sure you won't get an explanation that you are looking for. You are asking people which AV they think is best for them. This will vary on person and the reason they use their chosen AV.
On my work PC I have to use Symantec so for as my company is concerned that is the best. On my home desktop and my wife's laptop we use Avast. I chose Avast simply because it was recommended on here and so far have had no reason to change.
Just keep in mind that if you were to run three different AV's on the same comp you might notice that each one will pick up something the others didn't. It is a lot like running three different spy-ware and mal-ware programs. They will pick up some of the same but can also pick up other items that the others missed.
As long as you pick a reputable AV and practice safe surfing you should be OK. Just find an AV that you are comfortable and stick with it.
