I avoided AV software for most of my life. Though, when I worked as a student admin, I would always install AV for the majority of my users. Most users (especially older) simply could never learn not to download that cool new 'freeware' app or game or not double click a downloaded exe (the fact that hidden extensions are still the default on Windows OS is absurd).

As a more savvy user, I did not desire the typical AV bloatware (Norton, McAfee, etc) stealing up half my cycles and spinning the hard drive without pause. I knew enough not to try and 'open' resume.doc.exe.

However, AV's have trimmed down, SSDs are becoming more common place, and it seems the biggest attack vector is browser based. For the last few years, I've run a few different AVs (Kaspersky, ESET, Bitdefender are decent).

I run adblockers, don't install Flash games or Applets, but it is nearly impossible to stop all browser based attacks. I'm not sure the AVs have helped much, but they give some sort of psychological benefit, at least.

There really is no good solution anymore unless you're willing to give up 90% of the web (via NoScript or using a primitive console based browser). I believe the future for tech-aware users will be browsers in some sort of container / VM that reset themselves upon each session, with absolutely no control to the file system or data from other sites.