My Mega ranking
Some good fucking food: Froslass, Scolipede, Malamar, Drampa, Falinks
Leaves me with a strong impression: Clefable, Victreebel, Starmie, Skarmory, Emboar, Eelektross, Chandelure
Solid, but not especially remarkable: Dragonite, Excadrill, Scrafty, Chesnaught, Delphox, Floette, Dragalge, Hawlucha
I see the vision, but it’s not my vision: Raichu X/Y, Meganium, Feraligatr, Zygarde
Maybe take these back to the drawing board: Greninja, Pyroar, Barbaracle
Anyway, I was looking through some of the form data texts to see if any of the new Mega Evolutions change the Pokémon’s category in the Pokédex (since forms have been increasingly allowed to do that), and indeed, two do: Feraligatr, the Big Jaw Pokémon, becomes Mega Feraligatr, the Double Jaw Pokémon, while Drampa, the Placid Pokémon, becomes Mega Drampa, the Imposing Pokémon.
(I also noticed that Pumpkaboo and Gourgeist’s form names have been changed from Average, Small, Large, and Super Size to Medium, Small, Large, and Jumbo Variety. Presumably they’ve had to rework these two a bit to account for the fact that all Pokémon can be of various sizes now.)