Which is the best popular passenger planes boeing 737 or Airbus a320neo?

Which is your favorite airplane 787 dreamliner or Airbus a350

Is 787 dreamliner and Airbus a350 becoming popular

Which airlines are the best popular in United States

There's no popular passenger plane. Passengers try to book the cheapest flight. They could care less about which type airplane they are flying on.

That's really an immature question. You can't really compare the two.

Which measuring stick you're going to use? Passenger preference? Most people can't tell one plane from the other and don't really care which one they're on.

Orders? Airbus introduced the A32Xneo well before Boeing introduced the MAX version of the 737, so Airbus enjoys an order head start. Deliveries? The production of both models is just ramping up so it's too early to tell which one will take the lead, though with four A320 family assembly sites around the world Airbus will likely outproduce Boeing, which lacks expansion space at its Renton, WA factory. On the other, hand issues with the Pratt & Whitney GTF engines have delayed the delivery of some of the A320neo and A321neo aircraft to customers while Boeing is having a much smoother time delivering the MAX.

The 787 vs. The A350 contest is also not that cut and dried. The 787 enjoyed an huge order head start, but the problems with the supplier chain and then the delays in flight testing and the need to modify the first 64 airframes have cut into Boeing's lead over the Airbus. Airbus' initial response to the 787, the stillborn XWB was widely criticized by the potential customers forcing Airbus to abandon it and start with a clean-sheet design.

The 787 and the A350 only partially overlap in their respective market segments. The A350-1000 is going after the larger Boeing 777, not the 787-10. It also didn't help when Airbus all but abandoned the A350-800, the smallest version of the A350 family hoping that the updated A330neo-800 will fill that gap, however the it is not selling well. Hawaiian Airlines, for example, initially ordered the A350-800s then was forced switch to the A330-800. When it became clear that Hawaiian may end up as the sole operator of the A330-800, Hawaiian cancelled the order altogether and ordered 787s instead.

Airbus has 20% more orders for A320 family aircraft than Boeing has for B737. A320 has been outselling B737 every year since 2002.
The A320 performance are not affected by distorted air intake the Boeing needs owing to his too short landing gear; and the base design is 20 year more recent. That makes the A320 objectively better.