In my youth i gave up alcohol for a significant break on car insurance. My "cocktail" of choice was Schweppes Bitter Lemon with Angostura bitters. I consider Angostura the only true aromatic bitters.

I subsequently switched insurance carriers and resumed alcohol, and Schweppes stopped making Bitter Lemon. I switched to tonic water and bitters, for those sober occasions.

Recently Angostura has created a product called Lemon, Lime & Bitters, but it appears to be readily available only in the Eastern Caribbean (in my experience).

I recently learned of a recipe for a breakfast treat: half a grapefruit, liberally doused with bitters, then broiled (yup, in the oven, under downward radiant heat). The heat loosens the flesh from the skin and membranes. The original recipe also calls for sprinkling on demarara sugar before broiling, but i find it dissolves in the grapefruit juice rather than carmelizing, and does little to enhance a good grapefruit.