Malwarebytes and Microsoft Security Essentials have been my trusted "go to", anti-malware and anti-virus software for at least the past 5 or six years. I have never in the time that I have been using them, have ever crossed anything that between the two of them wasn't detected and removed.
(image courtesy of isupportu.biz)
I've seen some very heavily infected machines where the owner looked at a lot of porn and very shady sites, these two cleaned it right up. I have seen machines complety unable to boot or were so slow when they did boot into WIndows that it took 30 minutes for the desktop to load. A full scan with Malwarebytes and Microsoft Security Essentials cleaned both machines up and they both ran like they were brand new.
Never had a problem out of them, I recommend them to anyone I do work for, as well as for my friends and family. I've tried 90% of the available anit-malware and anti-virus software out there, including the paid/pro versions. I've used Norton's security suite and McAfee in the past, both are huge resource hogs and they let a lot of things get by them. Not worth it in my book. I have also used Avira, AVG, Comodo, Avast, Panda, Trend Micro, Bit Defender, Kaspersky, Vipre, and ESET anti-virus programs in the past as well. They are all decent at detecting and removing malicious items and they are all pretty lightweight on using system resources. I have heard that Norton has slimmed down the huge amount of resources their programs use but I'm not convinced. Also their detection rate is too sub par for my taste. I have also used Combofix, Spybot, Super Anti-Spyware, Hitman, Spyblaster; just to name a few of the anti-malware programs I used over the years. In my professional opinion none of them compare to the combination of Malwarebytes and Microsoft Security Essentials. I don't work for or am affliated in anyway with either company, they are two stellar products, it's just that simple.
Now of course if your a using a Mac, then MSE and Malwarebytes wont work for you. Yes Apple fans everywhere, Macs can and do get infected everyday with viruses and malware, a lot of the time because their owners foolishly buy in to the old adage, "Macs don't/can't get viruses" and they don't have any form of anti-virus installed. Really? No software is immune to infection. I've seen quite a few Mac's infected with viruses over my career as an IT technician. However Sophos is a great anti-virus that I've used on Mac's in the past and I know several people that use it on their work and personal Mac's and they love it. Also AVG, Avast, Avira, BitDefender, ClamXAV, Kaspersky, and ESET; all have versions of their software for Mac user's.
If you are running any version of Linux, like Ubuntu, Debian, Fedora, openSUSE/SUSE, Mandriva; just to name a few, you can probably get by with just using ClamAV. Linux is a very secure system and it's very hard for viruses/malware to infect a Linux based system. However if you feel that isn't sufficient enough protection then there are several anti-virus alternatives available for Linux users. Comodo, Avast, AVG, Avira, BitDefender, Panda and F-Prot.
If your curious about trying out Microsoft Security Essentials or Malwarebytes, just follow the links below to get more information about these two amazing programs and find out where you can download them from.