I'm an IT person.
We have been trying all different types of AV software lately.
However Norton is the best out there but their down fall is the fact that it does bog your computer down by up to 30%. Norton is always the first to update their virus database.
We tried AVG, however they are not the fastest when it comes to upgrading their database, they do not hog a lot of system resources as Norton does, but the downfall is the fact they they aren't the the fastest when it comes to updating their database especially their free version which leaves you open for even days at a time.
We tried Kaspersky as well, but we didn't like it and the fact that the program leaves a port open all the time for updates just kinda rubbed us the wrong way.
We are now using ESET NOD32 and by far it is the best that we have seen, they update their database extremely fast, as fast as Norton does. It uses the least amount of system resources as the previous ones, and as a matter of fact, you don't even know that it is there unless you have a problem.