Here is what the AI said:

Okay, let's break down which Chartreuse substitute (Génépy or Faccia Brutto Centerbe) works best for specific, well-known cocktails that traditionally feature Chartreuse.

My primary consideration for "best" will be which substitute most closely maintains the intended balance and flavor profile of the original cocktail, focusing on how Chartreuse functions within that specific drink.

Chartreuse Cocktail List & Best Substitute:
The Last Word

Original Chartreuse: Green Chartreuse (equal parts with gin, Maraschino, lime)
Function of Chartreuse: Provides the intense herbal backbone, bitterness, and a significant portion of the sweetness and high proof, crucial for balancing the gin, lime, and Maraschino.1
Best Substitute: Faccia Brutto Centerbe
Why: Centerbe is designed to emulate Green Chartreuse's complexity, high proof, and strong herbal/bittersweet profile. It will come closest to replicating the depth and balance of the original Last Word. Génépy would be too light and less assertive, resulting in a significantly different (though not necessarily bad) drink.
Bijou

Original Chartreuse: Green Chartreuse (with gin, sweet vermouth, orange bitters)2
Function of Chartreuse: Adds herbal complexity, a touch of sweetness, and bitterness, playing a key role in this spirit-forward cocktail.3 It's meant to be a prominent flavor.
Best Substitute: Faccia Brutto Centerbe
Why: Similar to the Last Word, the Bijou relies on the bold, multifaceted character of Green Chartreuse. Centerbe's robust profile is essential to achieve the desired depth and interplay with the gin and vermouth.
Naked & Famous

Original Chartreuse: Yellow Chartreuse (equal parts with mezcal, Aperol, lime)4
Function of Chartreuse: Contributes a milder, sweeter, honeyed herbal note that bridges the smoky mezcal, bitter Aperol, and tart lime. It's less about raw power and more about integration and nuance.
Best Substitute: Génépy
Why: While Centerbe is closer to Green Chartreuse, Génépy's typically milder sweetness and more floral/piney herbal notes are often a better fit for the role Yellow Chartreuse plays. It allows the other ingredients to shine while adding a complementary herbal layer, without overpowering them as a bolder Green Chartreuse substitute might. You might need a slight adjustment to the amount depending on the specific Génépy's sweetness.
Champs-Élysées Cocktail

Original Chartreuse: Green Chartreuse (with brandy/cognac, lemon juice, simple syrup, bitters)
Function of Chartreuse: Adds a sophisticated herbal layer, complexity, and balances the sweetness and acidity.5
Best Substitute: Faccia Brutto Centerbe
Why: The brandy needs a strong herbal counterpart to create a harmonious blend, and Centerbe provides the necessary depth and assertive character that Green Chartreuse offers in this cocktail.
Alaska Cocktail

Original Chartreuse: Yellow Chartreuse (with gin, orange bitters)
Function of Chartreuse: Provides the dominant herbal and slightly sweet flavor, making it a "greener" Martini variation.
Best Substitute: Génépy
Why: The Alaska benefits from the slightly softer, more aromatic, and less aggressively bitter profile of Yellow Chartreuse.6 Génépy, with its generally milder herbal notes and lower intensity compared to Centerbe, can mimic this role more effectively.
Nuclear Daiquiri

Original Chartreuse: Green Chartreuse (with rum, lime, falernum)
Function of Chartreuse: A significant contributor of complex sweetness, high proof, and intense herbal notes that define this powerful drink.7
Best Substitute: Faccia Brutto Centerbe
Why: This cocktail relies heavily on Green Chartreuse's punch and unique flavor. Centerbe's robust herbal character and comparable ABV will stand up to the rum and lime, providing the necessary "nuclear" kick.
Greenpoint

Original Chartreuse: Green Chartreuse (a Manhattan riff with rye, sweet vermouth, Chartreuse, and orange bitters)
Function of Chartreuse: Replaces the traditional Angostura bitters, adding a much more pronounced and complex herbal bitterness and a touch of sweetness to the rye and vermouth.
Best Substitute: Faccia Brutto Centerbe
Why: The Greenpoint calls for the bold, bittersweet, and herbaceous qualities of Green Chartreuse to alter the Manhattan profile significantly. Centerbe's intensity and complexity are crucial here.
General Rule of Thumb:

If the cocktail explicitly calls for Green Chartreuse and it's a primary, assertive flavor: Faccia Brutto Centerbe is usually the better choice.
If the cocktail calls for Yellow Chartreuse or requires a more subtle, less intense herbal note (where Green Chartreuse would be too dominant): Génépy is often the better choice.