Recommended AV please

When my licence for EST ran out I decided not to renew as I was experiencing the failure to clear the Sandbox error  Since then I have tried Bitdefender free version and am having all sorts of issues with compatability  So I would like to know what other people use as their AV (if possible free)  I understand now that it is possibele to use ESET issue free so maybe I should return to that  Please let me now what you recommend