I vote for Microsoft security essentials. It is very light weight, you will not even know its running in the backround. I have tried AVG, Macafee and Norton. They slow down your system. Stuck to Security essentials for the last 2 years with no issues at all.
I prefer Kaspersky Internet Security, Its protects users from entering suspicious site and also it serves a Anti Virus
First I acknowledge Norton antivirus and security products used to be undesirable for many reasons I don't need to get into for my answer. Some years ago Norton completely overhauled their software and since then in most (not all) creditable reviews they come out #1. I've used Norton for about 5yrs now and it's been very good to me. It takes less than a minute to install, is very light on system resources and has a very high detection rate with few false alarms. Thanks for asking, PugDaddy
I have personally experienced With KesperSky and i have found it the best antivirus software so for. Esset and Avg were also good but Kesper Sky on No 1 for me.
Go with McAfee It's nice doesn't hang your system and pretty much catches everything because i'm using this
microsoft essentials - My personal Experience its good detect approx all thread, auto-scan your external media, and update regularly.