For browser, I use FF for most, Chrome next, and the others when forced. No particular reason.
For "security", I use only free, and for many years now, only what Microsoft provides. Any "security" which has a paid element has job 1 of getting paid. This means trying to prove to you it has value, which means they MUST give false positives so you do not forget it is "on" and protecting you from the boogie men and women. This is mainly an issue with their WAG settings, what they call heuristics. This WAGuessing is why you will almost always see instructions to disable your security software when installing software... I test our software using VirusTotal before upload, and will often get a false positive or two from some of the outlier "security" companies. Even the "majors" give false positives from time to time,. In the last six months, compressing a setup file for online use will nearly always trigger a false positive - so the result is wasted bandwidth due to the false positives, since I can no longer compress our setup files. (The reason is many will believe the false positives, which means I lose customers since many "believe" the false positives.)
The only real safety is the nut at the keyboard not doing silly things, and making sure to have a good recovery plan. No software can predict in advance (what heuristics tries to sell us) what someone will dream up. McAfee made his fortune selling his "tonic", and has confessed that no paid "tonic" is needed nor can any "tonic" actually protect us. Norton was good when it was Peter's company....
Interestingly, I recently changed routers, and it comes with an optional "security system". The "security system" gives me a warning when reading a safe major newspaper site, as one of their ad services is being flagged as nefarious. I will not be using the "security system" beyond the trial, but I was curious.