Note that Fee Brothers Old Fashioned Bitters
do contain angostura bark. Also, if you can find a bottle, Regan's Orange Bitters are another excellent choice - I have a dwindling bottle of it, along with the Fee's orange.
Fee's also has peach, lemon, and mint bitters; I keep the peach on hand as well, but haven't seen or tried the other two. I always keep Peychaud's on hand as well.
Then there is another whole class of bitters: beverage bitters that are often consumed as-is or on the rocks. Campari would be a good example of this, along with a variety of French
amers and Italian
amari. Vermouth and other aromatized wines (Lillet, Dubonnet, etc.) arguably fit this category as well, and Punt e Mes is a vermouth that is spiked with extra bitters.
Oh, no! You have walked into the slavering fangs of a lurking grue!