The global feed on Iris is my top choice right now due to its degrees of separation settings from 1 through 6.
I turned off all my filtered relays I bought and have been running only free relays for a few days as a test.
I've been trying to find a way to onboard people without suggesting paid relays out the gate.
npub1p5ryszcvdca78jdp5ewhu67zpyfz042m7nrha6mqx7a8wakrqrkqre5ksj talked about the advantages of unfiltered relays a few days back. He has a fast, free relay he runs if you want to try it out.
wss://nostr.libertasprimordium.com