The best AV...
... is VirusTotal (http://www.virustotal.com/), and a good backup software in case of infection.
I have a PC since 1991, WITHOUT any AV, WITHOUT any firewall, and NO spreading infection so far (on Win95/98 and now W2K). And still, I used to visit sites like astalavista.box.sk. How? I know my PC very well, detect all strange behaviours, and in particular avoid running any strange exe. It's only since the last 2 years that I'm much more careful due to explosion of malware, and hence I use VirusTotal much more often, but only on files that I decide to scan. I won't let a stupid AV scanning a file that I know for sure it is clean since it is on my PC for years !
AV SW DON'T HELP YOU! They simply fuck up your PC, turning your superb ferrari into a 2CV ! AV are actually the only true viruses on earth, and you ought to pay for it??? What a joke!
I shut off the PC, pull the network plug. Restarted the PC, and run the AV. He detected ~20 virus. By comparing the new files on the PC, I noticed there was at least 50 new files that was created in the last minutes before shut off, and the AV only detected LESS THAN 50%. I copied those files to my own PC, and run a online AV scanner on it. The online scanner detected 90% of the files. Two days later, I rescanned the files, 95% was detected online.
The PC was completely unrecoverable !!! How would you trust any AV to correctly clean the machine, when YOU CAN SIMPLY BACKUP-RESTORE IT very easily, with 100% confidence on the result ???
If you understand computer a bit, you don't need AV ! AV simply sucks the power of your PC, continuously scanning and rescanning over and over the same files again and again. I doesn't make sense. Backup-restore and common sense is the best answer. AV are for neophytes and for company PCs only, and yet...