What antivirus you use and why?

COMODO Internet Security Free

CommonSense 2013 Premium Edition

MSE because it's free :)

Panda + Scotty (WinPatrol) + RegCure
the dream-team of free

if paid I think I would go NOD32

Kaspersky PURE. all in one, internet security, firewall, antivirus, password manager

Linux

None cuz #yolo.

Norton 360. For 7 years. Never let me down.

Kaspersky

Norton Internet Security

avg, simple and effective. costs nothing (unless premium) and cause i'm used to it.

ESET SS cause it's never done me wrong :p

Malwarebytes

Nothing.

I don't need no AntiVirus annoying me everytime I try to download porn!

Used to have Avast for years, but then I kept getting free licenses for Kaspersky Internet Suite from my bank so that's what I'm using now. Plus it seems to be great detecting trojans so there we go. Only thing that annoys me with KIS 2013 is the horrendous boot time worsening, used to be better with 2012.

Comodo Internet Security Premium. The #1 firewall.

I say Avast is teh best...just saying

Eset smart security. its the lightest of them all IMO.

When I read the thread title I immediately thought about the antivirus for the T-virus or bird flu. I use MS Essentials.

Edit: It has just occurred to me that MS essentials is useless against zombies. I guess I'll resort to tinfoil hats.

None.
I don't need an antivirus hogging CPU time!

What: Nod32
Why: I have been using it for 10 years and I have had no problems - it works.

Norton because it was free.