I definitely prefer KASPERSKY. Which I'll explain further below. However I believe that if you are relying on only one Internet security product you are in big trouble. For web surfing, on questionable websites, you need more than a firewall and antivirus.
First, You must learn how to virtualize, there are a few good free virtualization products out there. I prefer free Sandboxie, but there are other good ones out there. Others include Timefreeze, Cameyo, VM-Ware. The best way to deal with computer viruses is to not get them and these virtualization products allow you to either empty the sandbox, or keep the program or programs that you downloaded. Twice I got hit with FBI ransomeware while my browser was sandboxed. all I had to do was close the browser, and empty the contents of sandbox. The whole process took about 10 seconds. For about a the last year, I got tired of paying for security products, like bitdefender, that just did not work . So I ran free avast with free zone alarm firewall, and I used some type of free sandboxing or virtualization. I have since added Acronis 2014 which has a sandbox component, as well as allowing for frequent hard drive image backups.
With all of these long term giveaways going on, A couple of weeks ago, I had a opportunity to try Bitdefender Internet security, Kaspersky Internet security, and AVG security side-by-side on 3 comparable computers. The only real difference between the computers was that one had a 2.5 GHz processor, and the other two had a 2.1 GHz processor. All had 4 GB of ddr – 3 RAM. Bitdefender tremendously slow down the faster of the two computers. Also, it kept alerting me to trivial things all the time. Like do I really need to know that the update was successfully completed 15 times a day. All I really need to know is, if an update was NOT successful. KasPersky, on the other hand, just stayed quietly in the background without an excessive number of alerts. Given that these two programs are consistently rated in the top three, I would certainly buy KasPersky before Bitdefender. I am from the USA, but I have to give it to the Russians on this one, in the Internet security arena they kick the crap out of the Romanians. AVG seem to have the least impact on computer performance, but I am concerned that the recent tests show that AVG's detection rates have slipped. Still, if I sandbox AVG, I feel quite certain that my computer will be malware free.
I found Bitdefender's "safe pay" browser-tunnel to be excruciatingly slow. It was so bad that I felt, I could have driven to the bank and back, by the time I got my banking done using Bitdefender's safe pay.
So, after the 91 days of KasPersky is up, I will likely buy KasPersky or install a year-long AVG as my antivirus and firewall combination. If F-secure or Eset has long-term free trial is available, I might try one of those.
When going to questionable websites or downloading questionable software I will sandbox or virtualize the browser.
Prior to downloading anything I use virustotal uploader, which loads links or programs to a website which scans them with 52 online scanners.
I use hitmanPro and Malwarebytes premium as second opinion scanners prior to installing any downloaded software. I also use free ADware as a second opinion scanner for potentially unwanted programs (pups)..
For chrome and Firefox browsers, I have installed HTTP switchboard browser extensions, which blocks cookies, scripts, plug-ins, ads, XHRS, and just about anything else. You get to decide what it allows to get through