None of these malware scanners should be considered normal maintenance. They are extra tools to be used if malware is identified by your primary AV program or the machine exhibits behavior that is suspect malware (mouse/KB quirks, browser redirection, services or network oddities). Malware changes all of the time but there are "tells" of infection.
The first line of defense is your real time Antivirus program, use that to scan and clean up malware. If something is found and cleaned, it might be a good idea to run your second line of defense, the on-demand scanners.
These on-demand scanners should be downloaded new each time (an exception is Malwarebytes - keep that around), the engines change (not just the definitions) as malware changes - and it changes rapidly.
Malwarebytes and AdwCleaner are quick general use scanners
ESET is a good follow up.
Each scanner focuses on different criteria, so one might identify some malware while another finds other malware.
There are many other scanners in the toolbox, but they're more single purpose scanners or they target a specific type of malware.