any of suggest the best antivirus program

None, use Linux and forget about an AV

Hi, in free av you can use Avira or the new Kaspersky free suite, in paid version use Kaspersky but the best still is to be careful with what you download as well as the mails you open

Probably bit defender, a lot of people use it and it has a lot of useful features.

I am using ESET and i really like it! It is very aggressive and works very well!

Avast is pretty good

Kaspersky is good...

I would suggest you to try using eset antivirus or smart security. It's one of the most lightweight antivirus that you'll ever use and it does it job well.

Avira, hands down. Fast and no bullshit