Honestly, I'm liking megaevolutions less and less. They're giving them to already powerful pokemon that don't need them rather than pokemon that could use a boost both in power and visual design.
Mawile and Lucario are the only truly great looking ones if you ask me. Kanto starters, Mewtwo and Garchomp megas look less cool than the originals. Either make them look better or don't bother.
Pokemon that actually need megas would be...
Cacturne (Cooler design, better stats including speed. Maybe huge power ability)
Serviper (Fairy's weakness to poison could give Serviper it's time in the spotlight. Attack boost)
Fearow (Get it up to par with other flyers)
Kabutops (One of the coolest pokemon designs, needs more love plus one fossil should gain a mega)
Sunflora (Becomes grass/fire type. Huge special attack boost. New ability. Visually taller and cooler)
Masquerain (Gains water typing and huge stats boost. Design becomes more elegant)
Stunfisk (Get's larger and more stingray like. Huge special attack and speed boosts. New ability)
They should be giving megas to weaker pokemon to bring them up to par and give people other options to use rather than everyone using the same powerful pokemon. That way there would actually be hundreds of viable options to use and no "unusable" pokemon as people like to brand them. Making the already powerful pokemon more powerful is the wrong way to go and is just gonna push other pokemon further out of the spotlight.
Mawile and Lucario are the only truly great looking ones if you ask me. Kanto starters, Mewtwo and Garchomp megas look less cool than the originals. Either make them look better or don't bother.
Pokemon that actually need megas would be...
Cacturne (Cooler design, better stats including speed. Maybe huge power ability)
Serviper (Fairy's weakness to poison could give Serviper it's time in the spotlight. Attack boost)
Fearow (Get it up to par with other flyers)
Kabutops (One of the coolest pokemon designs, needs more love plus one fossil should gain a mega)
Sunflora (Becomes grass/fire type. Huge special attack boost. New ability. Visually taller and cooler)
Masquerain (Gains water typing and huge stats boost. Design becomes more elegant)
Stunfisk (Get's larger and more stingray like. Huge special attack and speed boosts. New ability)
They should be giving megas to weaker pokemon to bring them up to par and give people other options to use rather than everyone using the same powerful pokemon. That way there would actually be hundreds of viable options to use and no "unusable" pokemon as people like to brand them. Making the already powerful pokemon more powerful is the wrong way to go and is just gonna push other pokemon further out of the spotlight.