In truth, this is my FAVORITE AV but I can't really recommend it to the average user, since it's a bit more advanced as far as configuration and maintenance goes.
I've been using Symantec Antivirus Corporate Edition and currently its successor, Symantec Endpoint Protection. It negatively affects the start-up time of my laptop but once it's up and running, it's fine. Never had problems, I visit questionable sites with malware and it would provide great protection.
Having said that, it's a rare occasion for something to get past it.