Duckduckgo for everything.
At first, after the switch years ago, I'd occasionally fallback to Google to search for solutions or explanations of technical errors but I guess Duckduckgo got better and/or Google got worse and I no longer use any other.
A few days ago I tried Qwant briefly with the idea to try to change to non-US services, don't remember what for, and was not satisfied with the results. I did not try it for long enough to say it's not a good choice though.