Don't click "Yes" from shadey companies, don't run files from people you don't know, don't install crappy software, ect
Its no secret that digital pathogens are being created at a phenomenal rate - often much faster than we can keep up. I personally run the standard battery programs such as AVG antivirus, spybot, ad-aware, and spyware blaster. But honestly, I'm hardly conviced those are enough to keep out some of the more malicious stuff out there (Rootkits, keyloggers etc).
What programs do you guys run to keep out Malware?