Well, after a long absence, I think it is time for me to rejoin the discussion. I am going to be a bit gutsy starting off with a nomination of my own.
Pidgeot-Mega C -> C+
While I do not have any current results for it in top tier ladder, using this Pokemon in around the 1600s has felt wonderful. So, why is this Pokemon good enough to move up?
1.
Damage Output: While Pidgeot doesn't end lives like Hoopa-U or a similar wallbreaker can, it can gradually put dents in most teams. Very few Pokemon can take Hurricane into Heat Wave well, and the ones that can have definite counterplay both in Teambuilding and during the game (Heatran, one of the few Pokemon who can take the Pidgeot's attacks, has major counters and can be answered with other team members). No Landorus-T set can take two Hurricanes, and no fast Magearna set can take a Hurricane into Heat Wave. AV Magearna can take its hits well, but even it can struggle with Pidgeot for reasons I will cover later.
2.
Resistance to Setup: Pidgeot will not give the opponent an opportunity to setup with most of the meta. A setup Pokemon cannot switch into Pidgeot and expect to get out unscathed. Even something like Autotomize Celeteela will be damaged to the point that it can easily be revenged or even dealt with by another team member without loss. Volcarona has no chance setting up in front of Pidgeot, nor can Pinsir, Scizor, Gallade, Bisharp, Kartana, Mawile, and more. To Pokemon like Tyranitar, you can see what the opponent plans to do (generally speaking) by U-Turning into a counter or a check.
3.
Crippling Counters: Normally when a counter is presented, a Pokemon is forced to switch without any significant damage being done. The same cannot be said of Pidgeot. Hurricane has the Scald affect; even if the opposing Pokemon can take the damage itself well, there is always a chance for the opponent to become confused. While confusion is not as consistent as a Burn, it can be extremely powerful. Confusion can prevent a counter from healing itself, performing as a cleric, removing hazards, or merely stall an extra turn for an answer to be brought in on it. Of course none of this is guaranteed, but when playing with this Pokemon a decent amount, these affects will occur, and they will occasionally be powerful enough to maintain or completely swing momentum in your favor.
4.
Consistency: Pidgeot takes the very powerful yet horribly inconsistent move, Hurricane, and makes it perfectly accurate. You will always get the damage of Hurricane out thanks to this accuracy buff and Pidgeot's general speed. Speaking of speed, Pidgeot's is good. It is not quite as fast as Greninja, but it is not a slow Pokemon by any means. Of all the Pokemon in the S/A tier, only 4, Greninja, Greninja-Ash, Tapu Koko, and Mega Alakazam, are able to outspeed Pidgeot's 121 Speed without scarfs or speed buffs. If you include the B tier, only 1 more is added with Weavile joining the group. While Pokemon like Mega Swampert in the rain can outspeed it, Pidgeot still outruns the catalyst to this speed (Pelipper), ensuring that damage will be done. Some scarfers are also outsped by Pidgeot, such as Magnezone and Tyranitar. Having good and reliable damage output it extremely useful, and is more representative of a higher ranking Pokemon.
5.
Survivability: While Pidgeot is not a tank, it has been blessed this generation by the appearance of passive Pokemon, such as Toxapex. While Pidgeot may not be able to destroy Pokemon such as these (though such an occurrence is not impossible, for reason 3), it can Roost up and U-Turn out on them for little retribution from the opponent.
While I don't think Mega Pidgeot is good enough to move up too far, it is certainly better than the likes of Hydreigon, Kyurem, and even C+ Pokemon like Cofagrigus and Beedrill. Is there a reason why Pidgeot is just not worthy of moving up a rank, or should the big bird move up a bit? I personally think that Pidgeot could be B-, but I can understand that such a jump is too much and that a small increase would be best.
So, what is your opinion on this?