Somewhat late with this, but oh well.
For me, the Villager is the best newcomer so far, he's really wacky and Animal Crossing is a big series that really deserved it. I've only ever played a single AC game (New Leaf) and I only played it because of Villager making it into Smash, and I do like him, but I just didn't really want him.
I know Mega Man was the big fan favorite and most requested, and I was expecting him to show up, but I had never played a Mega Man game before then. I actually had no idea who he was until around Brawl speculation when he was popping up everywhere. His moveset looks really great though and I look forward to him.
Little Mac is... Interesting, to say the least. I'm not a fan at all and I only put him in third place because I dislike everyone under him more. His moveset certainly looks unique and refreshing, but I just can't say I like him. Even if I had played Punch-Out, I still wouldn't have wanted him, he's just... I don't know how to put it.
Rosalina by far has the most interesting gimmick, but I'm completely put off by her as a character. Maybe I'm just the genwunner equivalent of a Mario fan, but I just hate that this new face has become big enough to be included in Smash. It just feels like Nintendo pushing and I don't like it at all.
Greninja was saved the spot of last place by Miss Fit easily taking that cake. I like how he looks gameplay wise, and he was my starter of choice in X (along with Charizard), and I do like him as a Pokemon... But him being in Smash just rubs me the wrong way. I could just be angry about the loss of the Trainer though.
Of course that leaves Miss/Hee Fit in last place, I highly doubt that needs explanation. Sure it was neat as a "surprise! no one thought of this character!" thing, but the novelty has really worn off with the majority of the newcomers doing the same thing. She isn't even unique playstyle wise so there's really nothing redeeming.
I'm not trying to be negative about this, but this is really getting bad. Particularly with people going as far as trying to find unwantedexpected characters, and even believing something like Chorus Men will be in... The standards are really starting to drop to Miiverse level, I'm half expecting people to think Goku has a chance. The rest of the game looks great, the modes, stages, etc. But the characters are the meat of the game, and the single most important aspect for me, I'm not going to say the game is bad... But I really wouldn't want to waste my money on it if the one thing I care about isn't up to snuff, you know? I get that there are people who like it for the gameplay, but this is still about the characters at heart. If I was worried about the gameplay, I'd go play some other fighting game.