I set forwarders to Quad9 (9.9.9.9)
Used to do OpenDNS freebie servers (208.67.222.222 'n 208.67.220.220)...and still do at some clients, because OpenDNS seems to generally have faster response times, and for certain clients on a certain ISP have horrible response time to Quad9
But I started shifting most clients over to Quad9 about a year ago...since Quad9 officially states they allow use for businesses. And since Cisco bought out OpenDNS..."some" of the features of the freebie .222.222 and .220.220 servers have been depreciated. They still filter out known malware distie sites and phishing 'n stuff though. But...knowing Cisco...the free service may get pulled at some point down the road and I don't want to have an emergency trying to cut over all clients at once.
I've read some "comparisons" of the two..they're close enough in effectiveness.