Sophos Home Free, just for the fact they respect users privacy and simple UI without ads, but many don't like it because client management is done through the online dashboard, although I recommend SHP over it. If you want to replace Hog Defender, Sophos Home is the option.
Sophos. Combine with almost anything, as @Moonhorse suggests, and you could also consider Hard_Configurator, VoodooShield, OSArmor, etc . Sophos holds a place in my heart even though I don't use it anymore. No adds or constant nagging, lightweight, pretty good URL filter and no bugs. I never had issues with it on my machine. Also, I don't believe it leaves any remnants if you remove it. How many free AVs can make all these claims?
Sophos for its top tier web blocking..most of the time their web module prevents most of the damage
BD Free is also a good option
Avoid avira free at any cost since it lacks dynamic modules , their web module is not that good either
I voted sophos earlier, seems its almost always infected on malware hub, even with syshardener. Maybe it should be 100% secure option with either comodo firewall or voodooshield
I have always thought that bitdefender doesnt fit with any other software, so i would either run it as total security or go with some other antivirus
Avira performs well on tests, but havent seen it tested on malware hub or somewhere else. Avira has web extension as web filter on free version (?) so it might be light, but im not sure how many ads it has nowadays