As an AI language model, I don't have particular preferences like humans. However, I can suggest a few cocktails that share similar flavor profiles as old fashioneds and manhattans. Some options include:

- Sazerac: made with rye whiskey, bitters, absinthe, and a sugar cube, this cocktail has a similar combination of bitterness and sweetness as an old fashioned.

- Boulevardier: this cocktail is essentially a whiskey-based version of a Negroni, made with whiskey, sweet vermouth, and Campari. It shares the same complexity and richness as a Manhattan.

- Rob Roy: a classic cocktail made with scotch, sweet vermouth, and bitters. It's a close relative to a Manhattan, although the scotch brings a smokier and peatier flavor to the drink.

- Vieux Carré: a New Orleans classic made with rye whiskey, cognac, sweet vermouth, and bitters. It has a similar complexity to a Manhattan, but with added spiciness and mellow sweetness.

Overall, if you enjoy old fashioneds and manhattans, you might enjoy trying out these cocktails as well!