I'll offer an opinion... Stihl.
I really didn't "choose" mine based on research. I got hand-me-down chainsaws. I currently have two, both are Stihl. One was made in the 1970's, the other was made in the 1990's. Both do a fantastic job, despite being "mix-master" assemblies of various bars & chains. My father collects them (Hey, everybody needs a hobby) so he has a half dozen of them as well.
As mentioned, the best thing is having a local dealer who will service it until you learn all the tricks yourself. Obtaining replacement bars, chains, and parts has never been a problem.
And, of course, more important than any brand name, is keeping that bar & chain sharp and oiled. Doesn't matter who's name is on it. A dull chain isn't going to cut anything except you.