I personally think it is latios or latias but tropias is good.
with a flying pokeball
chincypops
zekrom the legendary
its an opinion question really. so i think Dragonite is the best.
Gyrados maybe.
pelipper
ANYWHERE
Rayquaza is the best, but non-legendary is Salamence.
I don't preferably like legendaries, but Lugia is definitely the best flying type in the onto region
Staraptor Articuno Zapdos Moltres Pidgeot
Winonna is the 6th gym leader and she uses flying type Pokemon. I'd suggest using a Pokemon with electric or flying type attacks.
There is no best Pokemon. All Pokemon have type advantages. My best advise is to get a flying Pokemon, an electric, a grass, water, fire, and a rock/ground Pokemon (Geodude is good)