For my clients, it's important to know what kind of first (or business!) class they want. If you want the most formal and elegant service, at the expense of a little warmth and personal connection, Japan Airlines or Singapore is for you.
For a good balance of friendliness and formality, Qatar Airways delivers, while also having the world's best business class, by the way.
However if pure fun, flying as the amusement it may have felt like in the early days of commercial air travel, Emirates is the move. They have all the luxury of course: the Dom Pérignon, the caviar, the sky suites. But they also are aware that you're on Emirates First Class, dammit, and you're here to have fun, not eat a meal and go to sleep.
The service is approachable, they get to know you, they of course don't treat you like a close friend immediately, but you can easily find yourself joking around with the crew within a couple hours of the flight. The snack basket is full to overflowing, and the gold trim is everywhere you look. It's Mar-a-Lago in the sky, pure excess.
The onboard A380 bar brings the whole experience together. The crew invites you to take a photo behind the bar, they have a Polaroid camera and keepsake picture frame ready to go!
Here's one of my latest times in Emirates first, on their fifth freedom leg from Milan to New York. If you'd like to fly this too (and pay a fraction of the cost of cash!) let me know. Why not, it's Disneyland in the sky.