The best antivirus is you, since you know to not fall for phishing spam, don't use P2P to run cracked programs, don't visit shady websites, and install all security patches for Windows, Java and programs from Adobe.
That being said, have a look at https://www.av-comparatives.org/ and http://www.pcmag.com/article2/0,2817,2372364,00.asp .Don't be amazed if their ranking is different.
Hello Guys, Please suggest me which anti virus is best for windows7?

Chowhound
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GameSpot
Giant Bomb
TechRepublic