I actually really like AVG 7.5. Its what I use, but since having it, my computer has only been infected by a couple of trojans.
It'll get rid of a lot, but sometimes it won't, and instead of doing it automatically, will give you a simple guide to remove it yourself, so it still works.
Id rather pay for a good quality one than risk viruses etc. Whats the point of an Anti virus that doesnt do its job properly? As you mentioned above, you have only been infected a few times since using AVG7.5, ive never had an infection with NOD.