nostr default relays of major clients:
you want to add all of them for a simple reason:
that if you use damus you want to connect with all relays of amethyst users and vice versa

Damus default relays:
wss://relay.damus.io
wss://eden.nostr.land
wss://relay.snort.social
wss://nostr.orangepill.dev
wss://nos.lol
wss://relay.current.fyi
wss://brb.io

Amethyst default relays:
wss://nostr.bitcoiner.social
wss://relay.nostr.bg
wss://brb.io
wss://relay.snort.social
wss://nostr.rocks
wss://relay.damus.io
wss://nostr.fmt.wiz.biz
wss://nostr.oxtr.dev
wss://eden.nostr.land
wss://nostr-2.zebedee.cloud
wss://nostr-pub.wellorder.net
wss://nostr.mom
wss://nostr.orangepill.dev
wss://nostr-pub.semisol.dev
wss://nostr.onsats.org
wss://nostr.sandwich.farm
wss://relay.nostr.ch

amethyst relays pulled from:
https://github.com/vitorpamplona/amethyst/blob/7399afa648ece731688e4de33fe57c370d586399/app/src/main/java/com/vitorpamplona/amethyst/service/Constants.kt