I think the best would be the one you self-host with your own parameters. But other than that searx.space provide you with the ones up to date, sorted by speed etc… The one I use most is the anon.sx

As @NixBits@lemmy.ml said, the best would be self-host, but if you are looking for a public instance I recommend switching when one gets unreliable. They are listed at searx.space

In my opinion: https://searx.prvcy.eu/ and https://searx.fmac.xyz/

I use searx.be, I wouldn’t say it’s the best but it works most of the time.