You can go to nostr:npub1cmmswlckn82se7f2jeftl6ll4szlc6zzh8hrjyyfm9vm3t2afr7svqlr6f profile, he has a list of the most popular relays.

I like to test relays, I think I found a good combination. I suggest making a backup first because I lost some followed during the tests.

Summarizing a little my strategy.

nos.lol -> I use it for my personal feed, it's the most popular free relay, everyone wants to be there, it even comes by default in some clients, so I guarantee that I won't lose the notes of who I follow. I also use it as a backup/redundancy if any relay is down.

relay.nostrplebs.com -> is another great paid relay and has some very interesting services, I leave it activated for my global.

nostr.wine -> another very popular paid relay, I also leave it activated for my global.

filter.nostr.wine -> another paid relay, it is an aggregator, bringing notes from the most popular relays and has a great spam filter, turned on global. I leave it enabled for searches too.

relay.nostr.band -> use more specifically for searches.

nostr.mutinywallet.com -> you can't read from this relay, it just sends my notes to different relays.

Note, you don't want to be in too many relays as it will drain your battery, your data plan and your client may slow down.

lol I think that was my longest note. Sorry if I took too long.