Most overrated design-wise eh? Hooboy do I have a wall of text ready for this.
Alright, first thing's first, I know someone said it up above, but Mega Charizard X. Chill the ♥♥♥♥ out with that appearance brah, we get it - you're trying to be cool. You didn't need to nonsensically change your whole color scheme, from one that coincided with your alternative prospective starter pokemon's of water fire and grass, with blue, green and red, to black. You can't just come back with that like you're ACDC. You're not. And the blue flames, like your'e 2edgy4school; what is that?! Blue flames are supposed to burn hotter than red, if I'm not mistaken... but you're the PHYSICAL mega evolution, with "Tough Claws", and a higher attack stat! I've got news for you buddy, no matter how dark and badass you try and look with those Pablo-Picasso-blue-period flames leaking out of the side of your mouth like you can't control your own power, your counterpart is spittin' much hotter fire, because he can control the freakn' sunlight, AND literally; spits hotter fire with higher Sp. Atk. Why not just have your claws cloaked in blue flame?!? Too much??? Is THAT crossing the line, with your sudden black color scheme, blue flames, and mouth-fire???
Lemme stop digging into that ascetic Hydreigon wannabe though, to spout off what might be an unpopular one. Garchomp. What; wh-what is this. Is this what kids think is cool nowadays? What does it even want to be? A dragon? A shark? A jet plane??? I dont' care if it gets sand veil - there's no way I'd ever miss anything like that, sandstorm or not. Its belly is bright red and yellow like some glowing Lost Planet franchise weak point, it has spikes... that, are bone? Metal? A dorsal fin; for - you know, swimming and stuff - because yeah - it can learn surf. Not that you'll EVER see that on a garchomp, but hey. IT LOOKS COOL RIGHT. Especially with those tears; like it just starred in a Steven Spielberg movie against "bigger jaws". Oh yeah, and its head makes a lot of sense; turbines on the side of a falcon-esque cranium, with inlaid eyes like it's stealing Deoxys' facial features - and what's that, A BIG YELLOW STARBURST IN THE CENTER. Why? PROBABLY - because he runs into sh*t constantly, because he can't see ANYTHING on his left or right - with organic JET ENGINES blocking his ENTIRE PERIPHERAL FIELD OF VISION. But who cares, right? Because he looks soooooOOOOOO coohoohoohoooohhooalskfjdlksadjsafjdslkfjdsklafjds
Don't even get me started on Mega Garchomp.