OG-nostr for one. That is to say nostr as first envisioned, with outbox across the board and users spread evenly across 1k or more relays (no relay clumping), and anything requiring a global view either not part of client architecture or (when tech matures) achieved through decentralised means, such as decentralised indexing. Plus relays being financially viable.
You can also make a technical argument that a hacked-together AT-proto network consisting of self-hosted PDSs, custom scaled-down app-views and an alternate DID/PLC directory (i.e. all of it totally detached from any company) would actually be more 'bitcoin like' than nostr. With that you wouldn't have the "not your relay, not your notes" and "not your storage, not your media" stuff to deal with (it's all on the PDS and, critically, content addressed) and you would also have general scalability closer to that of bitcoin, especially with how ATproto handles lexicons. Of course the cultures of bluesky and bitcoin don't align well, but such an ATproto network can be implemented entirely outside of bluesky's purview, and some have been already by enthusiasts.
I myself am not interested in Nostr for max decentralisation or censorship resistance. Iām interested in Nostr for commerce, interop and the integration of e-cash, so the way nostr is developing is totally fine for me. But I can understand how a bitcoin purist would see it as anathema.