[Image: https://dottech.org/wp-content/uploads/2010/12/dotTech_AV_Comparisions_Revision_3_Chart_2.png]
[Image: https://dottech.org/wp-content/uploads/2010/12/dotTech_AV_Comparisions_Revision_3_Chart_3.png]
They're actually all pretty good so you can't go wrong with any of them.
I'm using avast because it has sandbox mode and is slightly less resource intensive.