I currently have two work stations. I work from a Windows 10 laptop and a Chromebook. Personally, I prefer the use of the Chromebook, as the system is much faster than Windows (and my laptop is rather good...quad-core CPU and 16 GB of RAM), and I value my client's time they get per month. I also use google apps for business, so it's a win-win-win.
The Chromebook doesn't run .exe (executable) files, thus doesn't get viruses (in theory). Regardless, you can't run antivirus programs on it anyway (yet).
For my Windows 10 laptop, I've tried a few different options. I've had WebRoot SecureAnywhere, Avast for Business 2015, Windows Defender (also known as Microsoft Security Essentials or MSE), and MalwareBytes. WebRoot I obtained from Best Buy for free when I purchased the new laptop. I do enjoy the service, and the program runs extremely fast and has a very good detection rate...I'm frugal. I really prefer not to pay if I don't have to. Avast for Business 2015 was also very good, and it's also cost effective. The antivirus component alone is free, however if you want the other services such as the firewall, it's $2.00 USD a month. However, there are also really good free options. Two I know off the top of my head are Comodo Internet Security and 360 Total Security.
The reason I'm not listing Avast, AVG, Avira, or any other well-known company is simply due to the fact that they've recently decided to sell your browsing data for them to turn a profit off the free licenses they distribute. I honestly don't consider that safe, and I strongly prefer my data to be kept private...however I realize that's just me. I also look at this from a client's viewpoint. I signed a confidentiality agreement with each of them, and I wouldn't be honoring that agreement if I knew this was going on, and didn't do what I could to stop and/or prevent it.
Currently I use Windows Defender and MalewareBytes, along with Windows Firewall. While it's good to have an antivirus, you also need a firewall. If you're behind a modern router, that's great! They typically come with two built-in hardware firewalls which help protect your network. However, if you have a friend or family member come to your office and connect to your internet and their device is infected, that firewall built-in essentially is worthless as it's already penetrated the network by logging into the network. This is where individual firewalls, or software firewalls come into play. Ever since Windows XP, firewalls have come with every version of Windows. Typically, the Windows firewall is all you need. There are some instances where you'll need other options.
I hope this helps!