Averna, Montenegro, Nonino are all very tasty to my palate. More savory/sweet than bitter.
I absolutely love Braulio and put it in that same category.
Fernet Branca, Campari, Aperol, Cynar, yep.
I haven't had Branca Menta, Vecchio, or San Marco.
If you like bitter bitter, I suggest Fernet del Frate. It is in no way sweet to my palate, very much a truly and unambiguously bitter fernet. Took me a few drams to really appreciate it, but now, well.
Unicum ftw!