I always held high regard for both Avast and Nod anti-virus packages and I consider these the best of the best, in terms of features and detection prowess. Recently I have had more success disinfecting friends PC's with the latest versions of avast.
The bloat factor is my biggest gripe with most anti-virus software on the market, being an avid gamer, a small resident footprint is a must and avast delivers on all accounts. At the moment, the crown for the best anti-virus package definitely goes to avast.
The free home edition of avast can be downloaded here or you can buy avast and get free technical support amongst other enhance features and protection. If you buy more than one licence of avast, each licence gets discounted, great for the office.
avast! is the multi-award winning antivirus product line from ALWIL Software a.s., which is ICSA Labs and Checkmark certified (for both antivirus and anti-malware). avast! antivirus regularly receives the Virus Bulletin 100% award, for detection of 100% of in-the-wild viruses, and is an SC Awards winning product. avast! award winning technology provides powerful protection across a range of platforms and operating systems including Mac, Linux and MS Windows 95 to Vista 64-bit. avast! antivirus has strong self-protection built-in as well as anti-spyware and anti-rootkit technology, while at the same time delivering a high level of performance.
avast! antivirus software represents complete virus protection, offering full desktop security including a resident shield. Daily automatic updates ensure continuous data protection against all types of malware and spyware. avast! antivirus is certified by both ICSA Labs and West Coast Labs Checkmark.