Note: There are TONS of flying type Pokemon so I chose the ones that best represent Flying types as a whole not their secondary type.
10. Skarmory is Steel/Flying type Pokemon with Great Defense and decent attack. This Pokemon looks like a metal bird but it is slow for a flying pokemon and it's special attack isn't to good. On the other hand it has good abilities so you can't go wrong there.
9. Swellow is Normal/Flying type pokemon with good speed and decent attack. This pokemon has the ability Guts which raises attack by 1.5 when this pokemon has a special condition, it also can learn Facade( a move that doubles in power when affected by a special condition) by TM. These two things together make this a powerful pokemon when affected by a special condition. You may want to give yours a burn orb or black sludge item to get Guts and Facade going early.
8. Hawlucha is a Flying/Fighting pokemon that looks like a bird luchador. This pokemon has good speed and attack stats making it great for physical moves.
7. Braviary is a eagle-like Flying/Normal type with a good health stat and a great attack stat. This pokemon can deal tons of damage with it's physical moves and i suggest you make yours have the Sheer Force ability to make them even stronger.
6. Crobat is a Poison/Flying type Pokemon with great speed and overall decent stats. Crobat can learn lots of moves to poison the enemy make this pokemon dangerous. It is also a poison type one of the only types to be strong against fairy types/
5. Togekiss is a Flying/Fairy type Pokemon with excellent special stats. However this pokemon has poor attack and should only learn special moves in general. You should have yours get Serene Grace ability to double secondary effects.
4. Tornadus is a Pure Flying Pokemon(the only one asides from arceus) that has two form one focused on attack and the other on defense and speed. The incarnate form has the Prankster ability which makes moves that inflict status conditions go first. The therian form has Regenerator which heal this pokemon by 33% when you switch.
3. Mega-Pidgeot is Flying/Normal pokemon which has great special attack and speed stats. This pokemon has no-guard ability which boosts' the accuracy of moves coming from and targeting it to 100%, this may be risky but you get the move Hurricane at 100% accuracy!
2. Staraptor is a Normal/Flying type pokemon with a great attack stat and good speed. This pokemon learns a lot of physical moves like Brave Bird and Close Combat making this pokemon all the better.
1. Talonflame is a Fire/Flying type pokemon. This pokemon has a great speed stat and learns a lot of high damage moves like Brave Bird and Flare Blitz. This pokemon has the ability Flamebody which means when physical attacks hit there is 30% chance of burning them. If you find the devolved form of this pokemon in the XY friend safari it will have Gale Wings which make Flying moves go first.
That's Right priority Brave Bird
Powerful Mention Mega-Rayquaza as if the normal form wasn't enough they made this pokemon a mega form. It has Epic attack stats and greats stats all around. The reason this pokemon isn't on the main list it that it wouldn't be fair. It could beat everything asides from a really well trained Gale Wings Talonflame. Even then it'd be pretty close.