I have been using Bitdefender free for about 6 mos. on my new Asus N550 laptop and it has worked without a hitch so far. I installed it after reading about it's rewards and recommendations. I believe PC magazine was one source that gave the number 1 status. In addition to being free it has a set it and forget it interface. On it's own it gives your computer a complete scanning while the computer is idle. I also updates virus definitions daily.
I also think AVG and Avast suck. I would also like to add that any good hacker can get through most Antivirus programs..I suggest looking for (Internet Security Program)..rather than just a virus program..Also good to have..Revo Uninstaller Pro.. It's a god send program when it come to getting out a downloaded virus Fast....Try to get full and licensed programs... (Bitdefender) is a good program but for uninstalling, it is a pain in the Ass..It leaves crap everywhere (Revo Uninstaller Pro) again will also take care of that problem for ANY program...It uninstalls the program then does a folder sweep to get all the stays and left over stuff...