+1 for MSE and when it hits the fan , when all else fails..... prevx will kill anything , for a price £££
Free I would say Microsoft security essentials. Paid I would say Norton 360 or Internet securities. I have used both and neither one is very intrusive or resource heavy.
MSE, Avast and Avira I would say are the good free ones. It's not for every system though, MSE slowed down boot up of a celeron laptop by 2 minutes, and Avast can slow down opening some exe files as it tends to be suspicious about it and will decide to open a sandbox warning or not. Avira was probably my favourite, can't remember why I stopped using it!
Comodo firewall is fantastic along with their AV. MSE is good enough if you've not got a spanner behind the keyboard, as there are a few failings in its detection.
I use Avast, and have had no issues with it. Slows down boot time by like 2-3 seconds, which I honestly don't notice.
I have tried most of them and found that I like the idea of Avira for the protection but can't live without the silent mode of Avast. So Avast it is.
I use Comodo Internet Security Premium. The pop up boxes saying it's sandboxed programs, as well as the firewall notifications are annoying at first. They decrease as it gets used to more of your programs. But it's been doing the job for a while. I had to get rid of Norton though, something about paying for something I can get free bothers me.
I was happy using Avast for years but in the last few months Avast and Steam stopped playing nicely together---had to regularly disable avast to update steam. Just reinstalled so I'm giving MSE a try, seems good so far.
As a paid one I've had kaspersky for the past few years and it's always seemed to work well, not intrusive and scores well in reviews of detection etc. Not too expensive if you get and can use a 3 pc license as well, ~£8/pc/year as a student.
You really don't need to buy a license for personal use unless its for business purposes. Id get a free one like avast, which is lightweight. I know people on my street who pay 30-50 quid for norton and mcaffee which annoys me.
I prefer AVG which is free. It has daily updates. I have never been infected while running with AVG. The next good antivirus software is NOD.
+1 for avast! . It's the least annoying and has the smallest memory footprint, which is great for older machines. Plus it has great defense modules and pre-windows boot scan