I flew business class with Qantas, Singapore, and American Airlines. Here's how they compare — and which is my favorite.

I flew business class with Qantas, Singapore, and American Airlines. Here's how they compare — and which is my favorite.

I've flown business class a few times, and I've learned not all upgraded flights are created equally.Jill SchildhouseI've flown business class with Qantas Airlines, American Airlines, and Singapore Airlines.My Singapore Airlines flight had the most mind-blowing food and the comfiest seat.Qantas had a cool lounge, and my seat on American felt private, but Singapore was my top pick.Although I typically take at least 50 flights a year, I never turn…