Which Anti-Virus you believe most?

Often I have heard of Quick Heal, as the most reliable Anti-Virus available to us but due to recent experience I have uninstalled this from our system & have replaced with the Microsoft Essentials. Because of unknown reason the Quick Heal malfunctioned & then it didn't allow the system to even reboot in a natural way. In a more serious ways, this got the complete control onto the root level with not allowing us to do anything with the computer. As the system was getting hanged-up with a slight intervention, the system administrator couldn't take that on remote basis. I was afraid of the PC being getting format & I found myself lucky on that & the new windows was installed without impacting the storage & files in it.

Do you have such experience too with your computers?