PC World has new anti-virus ratings out for the New Year.
You can find the article here.
The article talks about how well the top paid anti-virus suites are doing not just in protecting you against known threats, but also emerging threats, such as banking-related malware.
Still the top rated paid security program: Norton 2011
PC World also rates the performance impacts of these program.
Lowest total memory use: Trend Micro, Norton, and Kaspersky.
Highest total memory use: PC Tools, G Data, and Bit Defender.