Back in pre-brawl days, the Geno topic was one of the bigger ones, though that was mostly due to constant argument about the character. I mean....he's got a surprising high amount of fans and like...no good reason to be in. Its just the perfect storm for that sort of thing.
As for Victini, I still say that it makes much more sense than Zoroark, though Smash fans seem to be sort of stubborn about their picks or sort of cling to ideas for a long time. I mean, it seems to me that most of the Zoroark support is based less around wanting Zoroark, but rather thinking that there has to be a 5th gen Poke, and that its inclusion has to mirror Lucario (Lucario being the first 4th gen Pokemon with a movie, just like Zoroark was the first 5th gen). Quite frankly though I don't believe that the circumstances then are the same as they are now.
Still that's my problem with a lot of people's choices. Its not about what would be most interesting as a fighter, but rather just trying to shoehorn in characters who are "next in line" due to status and just not caring that they don't bring much interesting to the table.