>>43046720I honestly like them all, but I'd have to say that Gengar got it the best.
M-Alakazam is cool and a logical expansion of Alakazam, but there's not much going for it tematically.
GMax Machamp also looks cool but is even less thematic than Alakazam. Unless I'm missing some mythological context, its hands just get orange.
Alolan Golem looks kinda dumb, but I like it enough in concept to not really care. A railgun with a beard made of iron filings like wooly willy is too creative not to love.
Mega Gengar perfectly expands on the rest of the Gastly line and the way that it pushes its way into the corporeal world (gastly is just a face, haunter is a head and hands, gengar is a full body, mega gengar starts touching the ground and even merging with it).
GMax Gengar is a step backwards, both figuratively and literally. I don't like it as much as M-Gengar, but Gengar's mouth becoming a gate to the underworld, as well as it just being a head and hands again, implies that it went back into the underworld halfway. That way if it eats you, it can shit you out in the underworld.