Well, I found when using AVG was that a lot of my computers resources were being taken up and so I then moved to ESET NOD32 -- offers high security to either business level or just home level and also I found barely takes up any of my computers resources.. So program wise, I use NOD32 Anti-virus, Firefox, CCleaner and general common sense to maintain my system(s).
Doesn't take a lot to stay safe on the internet, just think of the possible outcomes which could happen say if you downloaded 'cracked software'.. some people aren't always so nice so they might post worm viruses instead of the application you want.. and then you're bummed for a bit lol.