I started with Ryobi due to good experience previously when I managed an apartment complex. Not going to call it junk, but it definitely isn't built for my needs. Fine for someone building bird houses out of pallets like they saw on Instagram, but normal fixxer upper homeowner use destroyed the circular saw in short order.
Bumped up to Rigid. Much better, these actually lasted a couple years, but still issues. Couple tools that were damaged out of the box, a circular saw with a bent motor shaft that made the blade wobble, returned to the store immediately. A couple warranty issues that Rigid refused to take care of, and if I wanted the tool back, I had to pay the diagnostic fee. Luckily the Home Depot manager took care of me, gave me a new tool off the shelf and defected the old one back, even though it was out of the return period. Good on Home Depot, to hell with Rigid. Buy Rigid if they work for you, do inspect them immediately after you get them, and definitely don't buy them because you think the warranty is giving you any kind of extra value, because it isn't.
Bumped up yet again to Milwaukee. Same clan, different family, and this is my home now. Premium price, premium product, quality finally in line with what I expect a tool to have. Decent warranty, but I have no idea how it works, because I haven't needed it. Tools are small, nimble, and powerful. The Milwaukee circular saw that replaced the Rigid one above is every bit as powerful as any corded saw I've used.
This was a basically my final lesson in "buy once, cry once" as well. I'd be money, time, and hassle ahead if I'd just bought Milwaukee from the get go, and not faffed around with Ryobi or Rigid at all.