I love freeware.
I am running Comodo Internet Security without Comodo AV as I find little slowdown during AV updates & Comodo AV updates do takes little time to finish.
Its running light & provides excellent protection.
But you need to know atleast how autosandbox works & how to run programs out of autosandbox. Then you would like it.
I am running on Win 7 64 with no probs.
My config of CIS
Config - Internet Security
No CAV installed
FW settings - "Dont show popups" unchecked
General Settings - Interface - All the options unchecked, only "show popup messages" checked
GUI taskbar - Geekbuddy removed, advanced settings, watch activities, reset sandbox added.
Tasktray - advanced view selected
Password protection - enabled
CIS new version is going to be released soon. I have read in their forum that AV & related little slowdown during updates have improved & no slowdown now.
When it releases will try full suite i.e with AV installed
As @hjlbx mentioned, Webroot SecureAnywhere is very light. You may be interesting in this.
I personally feel that the static detection ESET provides (signature based detection/heuristics) takes the upper edge compared to KIS and EIS based on my experience and private testing. However, there are so many samples out there being released every day that it would be unfair to claim a product is better than another based on some private tests. Each Antivirus has it's strength, whether that be detection with good signatures/heuristics, zero day prevention protection (for example, good HIPS and Behaviour Blocker), web filtering (in case of malicious or phishing URLs), ...
Once the ESET HIPS has been configured, the results which are presented are much better than when it is on default settings.
Kaspersky have some nice features. Such as: Application Control. Please note, this should only be used on a system which you know is clean, if the system is infected when this is starting to be used then it can cause some issues. Some users have also reported some bugs with the Application Control. However, not everyone experiences these issues, and it can work very well.
Emsisoft Internet Security, I personally like their HIPS/Behaviour Blocker protection. They also combine dual engine scanning: they use the Bitdefender engine and their own engine (A squared). As well as this, the Behaviour Blocker combines their cloud technology to provide better user experience when auto-deciding actions (if the setting is enabled) and confirming suspicions of applications running on the system.
How much RAM is installed on your system, and what Operating System are you running? Each product has it's own minimum system requirements.
Emsisoft Internet Security - minimum system requirements:
Unless you have a rather outdated PC from the late 90s, the answer is most likely yes, assuming that you’re using Windows XP, Vista, 7 or 8 - with the latest service pack installed. From Vista onwards, all features are fully functional on x64 systems too. While running, Emsisoft Internet Security uses about 200 MB of your RAM, which is quite low considering the huge amount of signatures that it must load. If your PC has at least 1 GB of RAM, that will be perfect.
All of the products mentioned above are decent and good enough. As well as using a Internet Security program, I recommend using some on-demand scanners. Pick 2 or 3 of the following to use on-demand (I do not recommend using any more than 3, 3 is enough): Malwarebytes Anti-Malware (Free), Emsisoft Emergency Kit (If you decide to use Emsisoft Internet Security, this will not be necessary), ESET Online Scanner (If you decide to use ESET Smart Security, this will not be necessary), HitmanPro, HerdProtect or Zemana Antimalware).
You may be interested in a product called HitmanPro.Alert. The features for this software are quoted from the official website:
Alerts the user when critical functions of the browser are compromised by known and new banking Trojans, like:
Zeus
SpyEye
Sinowal (aka Mebroot and Torpig)
Ice-IX
Citadel
Cridex
Carberp
Shylock
Tinba
and many others...
Passively vaccinates the computer to make sandbox-aware malware belief it is attacking an automated analysis system, causing the malware the disable itself.
Supports all popular web browsers: Internet Explorer, Chrome, Firefox, Opera, Maxthon, Comodo Dragon, Pale Moon, Tor Browser, Avant Browser, Baidu Spark Browser, SRWare Iron and Yandex Browser.
Future proof technology does not rely on malware signatures.
Compatible with all antivirus programs and runs alongside any other security software.
The minimum system requirements to use this product are as follows:
Supported on 32-bit and 64-bit versions of Windows 8, Windows 7, Windows Vista, Windows XP, Windows Server 2012, Windows Server 2008 and Windows Server 2003.
As well as on-demand scanners, you can strengthen up your browsing experience with: an Adblocker - I recommend using uBlock, it has performed well for me and I has worked better for me based on my experience with other Adblockers available out there (Adblocking will help protect your privacy since advertisements can track you); WOT (Web of Trust), it will give you reputation information for websites; Click & Clean (clean your traces e.g. History after you've finished using the internet, this can help protect your privacy since it will help prevent any software from gathering this information which is running after using the extension).
You may also be interesting in using a Sandbox or Virtual Machine to test out new programs before allowing them to run on your system, prior to not using them before on your main system. This will help protect you in case of a malicious or potentially unwanted download.
As well as my above advice relating Sandbox and Virtual Machine, you could scan new downloads you are unsure of on VirusTotal to check what the different Antivirus scanners provided on VirusTotal think of the sample. Make sure to have the upload reanalysed and not check the last analysis.
Make sure if you decide to use Emsisoft Internet Security to be aware of the conflicts relating to VirtualBox and the Bridged Network.
There is no "best" AV, AM or firewall, and always will be.
My personal choice is Emsisoft Internet Security. Nice GUI, user friendly, easy to use, good protection, fast scanning, excellent customer support (you won't find any AV vendor with better support than Emsisoft!).
ESET Smart Security [Paid] - Light, highly configurable [HIPS, Firewall], high detection rate of zero day malware
Comodo Internet Security [Free] - Light, highly configurable [HIPS, Sandbox, Behavior Blocking, Firewall], AV component isn't it strong suit but with the other modules mentioned w/ proper tweaking , nothing gets passed it.
Emsisoft Internet Security [Paid] - Moderate use of resources [Bitdefender engine culprit] and good balance of automation and tweaking to fit user's needs.