There are four I picked:
Gligar/Gliscor - Flyscorpio Pokémon is cool and bulky, I would like it more if it wasn't so annoying competitively though.
Skarmory - Metal bird, Spikes and utility, very cool stuff to use both in-game and competitively. It was overpowered in Gen III competitive but it's still nice here.
Swablu/Altaria - One that feels unloved, but it has plenty of things to use such as Dragon Dance, Cotton Guard, and a Mega Evolution incoming? Not to mention it's the Challenges forum mascot.
Rufflet/Braviary - AMERIKUH!! Nuff said :P But in all seriousness this is one I quite like for its strength, and it's a patriotic bird which rocks.
Honorable mention goes to Pidove's evolution line, if only because of Grus from my White 2 Wedlocke, which lasted a long way but met her somewhat timely demise at the end.