Hi Omar,
We do not know the settings of the test, and the criteria. So what does this tell us all? In one test Bitdefender is number one, in another test it is number last.
You should just evaluate what avast as a AV-solution means for you! I know what I like in particular. It is reliable, does not carry things it should not. Very important thing for an AV-scanner, it has never harmed my OS. It silently does what it should in the background. Sometimes I use additional scanning (Fprot for Dos, yes it is still around), DrWebCureIt, Bitdefender online). What is striking that I do not get FPs that others flag because of heuristic scanning. DrWebCureIt flags toolbarcop and aimfix as probably malicious, typical FP's, Fprot, very reliable and profound, once found a decomposition bomb, Bitdefender never falsely flagged a thing. But after some time analyzing these things you know where dangers lure, and you take measures to avoid them.
polonus