Well...I would say Charizard, but that's clichéd, and I personally prefer Swellow as a pokémon.
I've never seen Noctowl, not really seen Butterfree or Pidgeot either.
However, Swellow and Staraptor are just "Search and rescue" birds, hardly battling. So, for that reason, I'm going to go with Charizard, as he's cool, flamethrowers Ash whenever they meet, and has taken on an Articuno.
I reckon if he'd appeared in the Sinnoh League, he'd have narrowly defeated Takuto's Darkrai.....he could've walked over Paul, but that wouldn't have been worth 3 episodes then..so I wouldn't have wanted that to happen.