We get asked a lot what AV (anti-virus) programs we recommend.  Here's our current recommendations as of June 2016:

 

Avasthttps://www.avast.com

The free version of this is quite good.  Our experience has been that it is good at blocking malware scripts on websites that other AVs miss.

The downside is that it's chatty.  You'll get pop-ups quite often with attempts to upsell you to a subscription.  If these really bug you, get the subscription.  It won't eliminate the pop-ups, but you get setting options that let you receive less.  Plus, it's a great program overall, so support it!  And, the upgrades do offer some real values.

Trend Micro
http://www.trendmicro.com/us/index.html

One of Troy's favorites.  When we asked Troy why he likes this one, he said, "It's just always worked well."  This may sound trite, but it's a huge endorsement.  Long term dependability in an AV is hard to come by.  What's great this year may not be great next year.

This is not a free program, so you need to buy a subscription.  But it's very worth it. 

AVG
http://www.avg.com/us-en/homepage

This has been ranked one of the best free AVs by industry sites for a while.  The paid version has some nice features as well.  If you download the free version, just be aware of what comes with the free version and what is a free trial service.

Malwarebytes
https://www.malwarebytes.org/

The pro version is a good one to invest in.  The free version of this is a good one to keep on hand as a fallback, in case your main AV gets compromised.  (It happens.  No AV is 100% infallible.) 

Malwarebytes Free does not conflict with other AVs because it does not actively monitor (that's a paid feature).  So, if you don't use the pro version of this, at least download and install the free version.