For Atlanta to Montpellier business class, Delta's Delta One Suite is the obvious home carrier choice, with a closing door, 1-2-1 layout, and Tumi amenity kits, connecting typically through JFK or Paris. Air France routes naturally through Charles de Gaulle with a lie-flat 1-2-1 product and genuinely good food and wine service, plus access to the La Première lounge if your connection allows. KLM mirrors that experience through Amsterdam, with the added charm of Delft Blue house miniatures handed out to business class passengers — a small touch, but a nice one on a long trip. Turkish Airlines connects through Istanbul, and while it's the longest routing geographically, the DO&CO catering and lounge are strong enough that some travelers pick this option specifically for the layover experience. British Airways and Virgin Atlantic both route through London with suite-style seats that include a closing door — BA's Club Suite and Virgin's Upper Class are two of the more private hard products flying today, and Virgin's Clubhouse lounge and social bar make Heathrow layovers more enjoyable than most.