Everyone has a different opinion about things, so the answer might vary. The SSBB Tier List says that the character with the best match-ups, advantages is Meta Knight, and the runner-up is Snake. I personally think Marth is the best, though he is 7th on the Tier List, which is out of 37 characters, that's pretty good. For more information, go on the Smash Wikipedia, which includes the full list.
Geno does not exist in SSBB. It is possible to texture hack to make a character look like Geno, but Geno is not a real character in SSBB.
It all depends on how you play if you like the quick and offensive people toon link is your best, if you like slow but massively powerful pick ike, ganondorf.
You can't. He's not a character that's in it
Charizard Bowser Ganondorf Meta Knight
Gecko OS through the Homebrew Channel.
rosalina is not a character in ssbb
No he isn't, he would be way to powerful, not to mention he isn't even from a Nintendo franchise.
No shadow is not a character simply because They decided to use him as a Assist Trophy.
he is not a playable character in ssbb
There is no Roy in ssbb. Roy only makes an appearance in SSBB as a sticker .He's not a playable character.
This character doesn't exist in ssbb.
Geno does not exist in SSBB. It is possible to texture hack to make a character look like Geno, but Geno is not a real character in SSBB.
he's not a character in ssbb so you can't get him
He's not as a playable character in SSBB, but you can use him as a Assist Trophy.
no
no
Mewtwo is no longer a character so you can't fight him in ssbb.