Detracting from the thread's title, best to worst:
I had little connection with Mega Man prior to his reveal for SSB4, I guess I only heard about him through some online Flash games like Super Smash Flash or Super Mario Crossover, but I think he adds so much awesomeness to SSB4 regardless. I love his moveset, I love how creative, diverse and unique it is, I love how it represents what the Mega Man series is about, and I love using him. Not to mention his amiibo looks awesome and is the only one I own as of now.
I heard of the idea of him being playable during SSB4 pre-release and found it to be a rather stupid idea, so I was really surprised to see him in the ESRB leak. I thought it was so hilariously stupid it had to be fake! Though when leaked video footage of Bowser Jr. and Shulk surfaced I instantly started to believe everything that was leaked, including this character, and I started to consider the idea as possibly awesome. A dog who summons ducks to attack? Yes please! Okay, it didn't turn out to be exactly this, but I really liked his moveset, which looked to be very inspired despite the lack of obvious potential from the source material. Him representing the entire NES Zapper series rather than just his one game is indeed awesome, plus it really fits him considering he looks like a Tex Avery character, a characterization which definitely fits his original role. Not to mention I actually played his game when I was a kid.
I was actually kind of anticipating him as a playable character in Smash 4 despite the Gematsu leak apparently destroying his chances, and his reveal trailer was personally the most hype inducing for me. The concept of a character with a crappy base weapon who can use many much stronger weapons with limited use feels very creative to me, and the limited weapon use doesn't feel too intrusive in the actual gameplay and sets him apart from other Fire Emblem characters with their personal and unbreakable weapons. I don't really like how sluggish he is, but I like playing as him.
I never took him seriously prior to his reveal, because I saw no potential in him and definitely didn't want him to have the Ghostly Adventures design (and also because I don't like the idea of two or more third-party characters from the same company... I thought Capcom and Namco were the same thing back then
), so when I saw him on SSB4's official site I thought "What the... are they serious?" even though I liked the fact they choose a cooler design. Then I understood why he was included (Namco mascot, pop-culture icon, Miyamoto wanted him blah blah blah) and I grew to like his inclusion. His moveset feels creative and fits him surprisingly well, and I love using him. I'm planning to get his amiibo because it looks really good.
I thought about the idea of playable Bowser Jr. in Smash a long time ago, probably in the early post-SSBB era, I already wondered how SSB4 would turn out to be like. But I rejected the idea rather quickly, as I thought it was a stupid one, and when I started to care about SSB4 pre-release I still thought he was a stupid idea. I mean come on, Smash Bros. won't get a secondary villain as a playable character anytime soon! So when the ESRB leak surfaced I was shocked to see him in the roster and he made me want it to be fake. Later leaked video footage definitely proved the leak to be real and I actually was pleasantly surprised to see how he turned out to be. The Koopa Clown Car indeed is a very creative idea and his moveset perfectly represents what his boss fights are about, something he does better than other playable villains imo and that's why I finally like him as a fighter. Though I'm not sold on the idea of Koopalings replacing him for his alt costumes, mostly because Bowser Jr.'s moveset doesn't fit them... like at all.
Never played a game from the source series and I have no interest in doing so, but I love his moveset. It is very unique and represents Animal Crossing as a whole very well. However, I don't like some of his alternate costumes which look unappealing. The pink-haired female one in particular, I know it may be an unpopular opinion but I find it to be very ugly.
After his reveal I managed to find a copy of Xenoblade Chronicles and I really like the game so far. However, while the Monado Arts system makes him unique, it doesn't really represent his game very well, because in the source game it doesn't have for purpose to just adjust your stats but to have many different effects on the fight (and btw, Buster is an offensive giant forward slash, NOT a stat-changing art... it should have been Enchant instead). Though I respect the design decision in a way, as the Monado in Xenoblade allows Shulk to have considerably more arts to use in fight than his teammates. Thus it makes sense to give the different Monado arts as one single special move, and for balance's sake making them all similar in a way (like as it is, stat changes) in order to not artificially and unfairly giving him more moves than other Smash characters. (They also put two arts - Jump and Smash - not from the original game, but eh...)
I love the Super Mario Galaxy references in her special moves and the Luma mechanic gives her a very unique playstyle. Using a Smash attack to combo to another with Luma to kill the enemy may be one of the most satisfying things ever in Smash. Though I'm baffled she didn't get the spin attack from Mario Galaxy (and by extension the one she uses in SM3DW). It would have made much more sense than that weird looking dash attack.
Never been aware of his popularity before the Febuary 2014 Nintendo Direct, though he was the one who made me ride the hype train for SSB4 with his reveal trailer. In fact, I think I found him to be one of the least memorable Assist Trophies from Brawl. I think the concept of a boxer in Smash Bros. was well translated, though I don't really like how "extreme" he his. Most notably because of that crappy recovery.
As someone who never played a Kid Icarus game, I'm pretty indifferent to her inclusion. I like her moveset for some unique and cool looking moves (like up Smash, nair, uair, Explosive Flame, Super Speed), but I also dislike how generic her default special set is (I know it was made generic to incite players to add some fantasy with customs, but still) and how laggy she is overall despite not being Ike or Ganondorf level powerful.
Didn't care much about SSB4 when she was revealed, I can't really have an opinion about how surprising she was, but I doubt I would have considered her prior to her reveal. I have to say she has a rather creative moveset, converting yoga poses to attacks is a cool concept I admit xD though the Sun Salutation projectile feels kind of forced. And I have to admit, she sometimes feels kinda weird in the game... for example beating Master Fortress with her felt really awkward to me.
I thought it was Mewtwo in the shadow. I thought Water Shuriken was indeed a weirdly animated Psycho Cut. Then the truth was reveal and I was mystified. Not because it wasn't Mewtwo, but because of the character itself - I thought it was the most random character ever. Even though I was aware of his popularity, I was too confused to really enjoy the trailer and many hours after the Direct I wondered why he was chosen in the playable roster. Now that this confusion is long behind me, I'm still not entirely satisfied with this inclusion, as Sakurai himself confirmed that he wanted to add a Pokémon newcomer for the sake of a playable gen 6 Pokémon, a logic I don't agree with. Though I'm starting to think that Charizard was meant to leave Pokémon Trainer from the start due to having enough star power by himself and the Trainer concept was meant to be transfered to generation 6 starters, but due to technical issues he ditched the concept and only kept Greninja - just a theory, but it's hard for me to believe that Kanto Trainer AND solo Greninja were both planed from the start. I'm also not a fan of his moveset, Water Shuriken and Shadow Sneak being charging moves contradicts their use in Pokémon games, and overall he kind of feels like another Pokémon thrown here rather than a character who represents what the Pokémon series is about. I don't really like his playstyle either. I don't think it's a bad inclusion per se, but he's my personal least favourite non-clone newcomer.
While I understand that Sakurai promoted her when she was probably already done as an alt costume because he didn't want to lose all the modeling and voice acting work done after realizing she actually wouldn't fit perfectly as a Marth alt for whatever reason, it doesn't change the fact she adds basically nothing to the game, both gameplay and series representation-wise. I understand why she's in, but I'd rather not have her in future Smash Bros. games.
Similar to Lucina, I get Sakurai didn't want to waste all the voice actor already done (and not modeling this time... he's just a palette swap) and promoted him to a fully fledged character instead of outright cutting him, but just like her he adds pretty much no added value to the roster. Like Lucina, I'd rather not have him in the next gen Smash.
It seems he has potential though.
