A low-alcohol chocolate bitters from long-established American producer Fee Brothers. Chocolate bitters go well with most brown spirits, especially rum, as well as sweet vermouth, and of course, these are excellent in creamy cocktails too (think White Russians).
A peach bitters from cocktail ingredient masters Fee Brothers. This is a long lost variety of bitters that has disappeared along with some of the classic cocktails it appeared in - try it (after a bit of research) in a Coronation or a Xeres.
A mint bitters from Fee Brothers, adding a fresh minty edge to any cocktail you might like. Fee Brothers have been making bitters since the 1950s, although they can trace their company history in alcohol back to the 1860s.
Another slightly crazy bitters from the minds of Fee Brothers - an orange bitters aged in barrels that were previously used to mature Ransom Gin, adding in some piney juniper and gin botanical notes to the mix.