AntiVirus, Internet Security and Total Security Performance Benchmarking by Passmark.

I actually never really paid attention to comparison/testing reports about Antivirus and Security Suites especially related with "best detection", "best removal" etc etc.. This, since I have my own opinion about this :-)
However, this is a different test, a performance test of several different Antivirus products and Security Suites/Total Security Products by Passmark.

- The Performance tests:

* Boot Time
* Scan Speed
* User Interface launch Speed
* Memory utilization
* Installation Time
* Installation Size
* Registry Key Count
* File Copy, Move and Delete
* Installing Third Party Applications
* Binary File Download Speed
* File Format Conversion
* File Compression and Decompression
* File write, Open and Close

- Overal Ranking in comparison with other products:

Click to enlarge

It looks like Norton Internet Security 2009/Norton Antivirus 2009 is a winner here in comparison with previous tests and older versions.

Anyway, "decide" for yourself and read the full report here: http://www.passmark.com/ftp/antivirus_09-performance-testing-ed1.pdf

Still, imho, the best way to decide what Antivirus/Security Suite to use (for best performance) is to install it and see how it runs on your computer. After all, every computer is different.
If it runs fine and you're satisfied with the Antivirus or Security Suite, then keep it.