This is a bit of a long one. I don't blame you if you decide to ignore this post.
- I really don't like Froakie and its evos. It's overrated, it gets unfair advantages over the other two Kalos starters (better HA, much wider movepool, two signature moves, etc.), and I don't like its design at all. I get why others like it, but I personally can't stand it. Charizard and Lucario may be overrated, but at least they don't piss me off like Greninja does. In fact, I like both Lucario and Charizard, despite their being overrated.
- The Fennekin line gets unfairly bashed too much in my opinion. A lot of people dislike it because of its ear hair, or it's not on four legs, or its "disappointing" movepool, or some other reason. Other than the movepool (which I believe is just GF screwing over Delphox in favor of the more "cool" starter), the other things are why I love Delphox. Its ear hair is a nice part of its design and it cleverly shows the progression between each stage of Fennekin's evolutionary line (unlike Froakie, who goes from bubbles to more bubbles to no bubbles and that ugly (imo) tongue scarf). I'm glad that it's bipedal so I could differentiate itself from Ninetales. And the movepool isn't even that bad, at least not as horrible as some people make it out to be. Two good STABs in Fire Blast/Flamethrower, Psychic/Psyshock, and some other nice moves like Calm Mind, Dazzling Gleam in ORAS, Grass Knot, and Switcheroo, among other things. Sure, it doesn't have as wide of a movepool as Greninja (seriously, how does a ninja have a wider movepool than a witch?), but it gets what it needs. Overall, I'd much rather use Fennekin over Froakie any day.
-I'm not sure whether or not this opinion is unpopular, but I don't want a Bug-type Mega Flygon. I never really saw Flygon as being a Bug type to begin with. I don't get why some people are so eager to remove its Ground type, when Ground is a much better offensive and defensive type. Flygon's Ground/Dragon type is fine as is. I'd rather have a Dragon that's outclassed by Garchomp than a Dragon with a worse type. Unique =/= Better in all cases.
- I dislike Pikachu, but Raichu is awesome.
- Misty pisses me off and while my friends were sad to see her leave, I couldn't be happier. Imo, every girl Ash has traveled with is far better than Misty.
- Sorry is this one isn't an unpopular opinion either. Even though there are some Pokemon games I like more than others, I don't hate any Pokemon game. Same goes for regions. Every game and region has its good and bad points, but they're all fine.
- I prefer Mega Evolutions over Cross-Gen Evolutions. With regular evolution, you can't go back to the previous stage, and in most cases, the evolution outclasses the pre-evo rather than just improving it. That usually leaves the pre-evo left aside in favor of its evolution. (i.e. Sneasel is cool, but rather weak. Perhaps an evolution will improve it. Enter Weavile. Sure, it's a massive improvement over Sneasel, but then it basically replaces Sneasel, since who would still use Sneasel over the faster, stronger Weavile? Now, instead of being improved, Sneasel is left behind and forgotten, outclassed by its evolved form.) Megas, on the other hand, provides its base form with a great boost, while still leaving the base form the same. Thus you don't lose your Pokemon in order to make it better. With regular evolution, you must choose to either leave the Pokemon the same without improving it (thus remaining underpowered), or evolve it to give it the boost it desperately needs at the cost of never seeing the pre-evo again. With Megas however, the Pokemon can get the boost it needs to kick butt and still remain as it is. Other than Eevee, I wouldn't mind if there were no more Cross-Gen Evolutions.
(There are exceptions like Chansey, which outclasses Blissey in Gen 5+ thanks to Eviolite)
- I like Emboar.
- Fairy is an okay type. I don't love it, but I certainly don't hate it either.
- Smogon is also okay. It's not that bad imo.
- I don't really care about the Battle Frontier, or even if it ever comes back.
- I EV train my in-game teams.