what antivirus or computer protection do you use?

Payed Norton subscription, recommend it.

Selinux + uBlock Origin.
For Win machines ESET is not voracious, secure, can get free key on month.

Common sense, it's superior to any antivirus.
Other than that I use firewall, in particular right now it's COMODO firewall. It's far from perfect, but it's free and doing it's job. If anyone here uses application-layer firewall and can recommend a better one - I would appreciate that.

I am a microcomputer systems and networks technician and my recommendation regarding an antivirus is simple, do not use antivirus, they only overload a process in the background for hours that can slow down your PC.

If I would recommend you use superantispyware (https://www.superantispyware.com) and ccleaner (https://www.ccleaner.com/es-es/ccleaner/download), two programs free version and with versions this is enough to have the pc clean of malware, spyware, phishing scams and clean cache of records and if you use a hdd disk perform the hard disk defragmenter monthly, in google chrome browser can use extension adguard adblock (https://chrome.google.com/webstore/detail/adguard-adblocker/bgnkhhnnamicmpeenaelnjfhikgbkllg?) for more security and if you regularly browse in known and trusted places for me the antivirus is totally unnecessary.

Superantispyware you must manually update the database from the same program and I would recommend doing a full scan the first time, then use the quick scan (activate rescue scan and scan boost in high boost for scan more fast) every 2-3 days to remove browser junk that is generated by browsing and ccleaner (disable cookies for dont lose login in your websites when you go to clean browser) the same, at least one once a week to clear cache and logs.

The same thing that you I say it was told to me by a computer teacher who gave me classes and I totally agree, if you know where you enter and what you download you will not have any problem, if you need to verify a file downloaded from the internet you can do it with superantispyware as well and this program can have it disabled so it doesn't work in the background. I have not used antivirus for many years and unless you are a total novice with the computer world or for older people who click on any spam ad without realizing it, the rest of the people with a minimum knowledge of computer science can survive those programs and browser extension

NOD32

None. + Common Sense = Never had any issues

Eset nod32

I'm using Windows base security one. I have grown to look after my PC and it has been lasting years on end. For malware, if I do something dumb and get it, I use IOBit Malware Fighter. For cleanup, I use IOBit Advanced System Care.

On the side of that, to keep myself protected and safe, I use WOT. It's a browser extension that works with pretty much any browser and allows me to stay secure where I browse. The rest, the malware and my Windows basic security is enough to protect myself from viruses. I don't download stuff I find sketchy and my antivirus picks it up anyway.

I've used to break a windows and having to reinstall it every 6 months as a kid, because I kept searching websites and downloading stuff that made me catch viruses and malware. My last windows re-installment was a couple of months back, after I've had it for 5 or 6 years running without issues. The issues was that my video card was not recognized anymore after I've made a PC upgrade and after failing to get any workaround, I decided a fresh install. That fixed my driver issue and another one for my mouse. If that wasn't an issue, I don't think I'd reinstall my windows as for me it's more of a hassle to put all my programs back together in order as they used to be.

View attached image.

Fanatical has some solid deals right now on Bitdefender products, including Bitdefender Total Security which I mentioned in comment above a few months back.

As I mentioned previously - The Total Security version of Bitdefender compared to the free version is a LOT. It has solid ransomware protection, firewall, mic monitor, web cam protection, an anti-tracker, Wi-Fi Security advisor, secure online banking feature, VPN, password manager which as a vulnerability checker and file shredder, file encryption, network threat protection, anti-phishing, speed booster, parental control features and a great anti-theft feature which will track the device you use it on and allow you to wipe your data if you need to. It also includes free 24/7 tech support.

It's on sale atm for $27.88, with the Bitdefender20 code applied at checkout it's $22.38. This is for a year and supports up to 5 devices.
https://www.fanatical.com/en/game/bitdefender-total-security

Here's the full page of the 5 products on Fanatical.
https://www.fanatical.com/en/collections/bitdefender

Personally I use the common sense that I've built up over the years along with the only application that blocks game cracks, Windows Defender with app & browser control off, as those are mainly related to Edge, while I use Chrome.

Just like @aerostatik said.

There is absolutely no need to pay for an AV anymore. Windows Defender does everything the paid AV programs do as far as providing adequate protection for free. And just don't click on any links you're not sure about or install a file from a questionable source. If anything, run the file thru VirusTotal before installing. I do this with any apk I download on my phone/tablet before Installing it as well as some files on my PC. That's honestly all you need. Before I realized that I was just using Bitdefender because you can get keys for 180 days for like 50 cents lol