Damus is the main one. I use Nostur a bit. Nostrudel.ninja as a web app. I also have Primal but I don’t use it much these days

You’re seeing different things on Primal because of the way it fetches notes. Instead of fetching them from your relays it gets them from their caching relay.

Nostur has a beta feature in the settings where it removes notes you’ve already seen. If you turn it off (or have it off already), Damus and Nostur feeds are similar.