This should be highly controversial.
It all depends on which games the characters have access to.
If Link has
every one of his games to draw items from, but Mario does not, Link wins.
If Mario has
every one of his games to draw items from, but Link does not, then Mario would win.
If they both have
every one of his games to draw items from, then it's either a draw or Link wins (depending on whether or not indefinitely stalling is a legitimate way to win). I don't believe that stalling forever should be a legitimate way to win, as you're not really even fighting anymore.
Which games should each get?
Should Link only get items from games that featured Adult Link? Just Twilight Princess? Or should he get them all, as each Link is reincarnated and so they all have the same soul?
Should Mario only get items from his "main series"? Only from games that featured Mario as an adult? Or should he get them from every game, even from the non-canon ones (like the CD-i games and Paper Mario)?
Sonic should in fact win this one, so long as he can go Super Sonic. Sonic might not be strong enough to wrestle Rangell from Ike's hands, but Super forms are immune to damage and much stronger and faster.
Meta Knight wins, as he can fly extremely fast and kill the Pikmin almost instantly. Or he could simply create a huge (relative to Kirby's world, but Olimar is the size of a quarter) tornado and blow the Pikmin into the air, killing them upon hitting the ground.
Pokemon Trainer Vs. Lucario
Alright, there's a fairly simple way to end this. Lucario uses Extreme Speed and kills Red. If a Pokemon of his uses Protect to stop Lucario, then Lucario can use Feint to get around it, then kill Red. If one of Red's Pokemon is faster than Lucario, Lucario can use Detect to stop it's attacks. Lucario's Roar can scare Red's Pokemon away. If Dectect doesn't work, Lucario uses Endure to survive any attacks. Lucario can use Substitute or Double Team to prevent him from being attacked. If he can't attack Red physically, a Vacuum Wave goes just as fast as Extreme Speed. Swift and Aura Sphere never miss their target. If Lucario is heavily damaged somehow, it can use Reversal. Red can't win.
Zelda/Sheik Vs. Ice Climbers
Zelda/Sheik wins, mostly due to the fact that the Ice Climbers die pretty easily and Shiek has Deku Nuts to stun them. If that doesn't work, Zelda always has Light Arrows.
?
I can't help with this one, but Young Link has Naryu's Love to protect him, Din's Fire if Roy gets close... Light Arrows...
Peach quite frankly just wins, as she kicked *** in Super Mario RPG and Super Princess Peach. Pichu's pretty fast and can hit hard with some moves, but Volt Tackle will inflict heavy damage. I believe Peach's umbrella also protects her, and she has a good amount of health.
Spamus wins no contest, as Fox/Falco/Wolf's machines can't compare to all of Samus's weaponry. Not even their Arwing/Landmaster/Wolfen can protect them, as Samus has a beam that goes through anything. Her Screw Attack leaves her totally immune to damage while in it, and her Space Jump lets her jump forever. Powerbombs can cause massive damage, along with Ice Missles and Super Missles.
Let's not forget Samus's Starship.
I can't help here, but Kirby can frankly dish out alot of damage, even with his small height. Riding on a Warpstar/his Starship can allow him to spam greatly while flying around really fast. Too bad Ghost Kirby is slow.
Diddy Kong wins, I don't know wtf you're doing here. Doctor Mario can't really do anything by himself. Diddy Kong has his Peanut Popguns (which actually do a fair amount of damage) and his Rocketbarrel Pack. And chimps are pretty darn strong.
?
Kind Dedede is strong even for his size, but I'm not sure about Wario's abilities.
Toon Link is very strong, depending on what he has access to.
He can't have everything Young/Adult Link has, as he's not in the same line of re-incarnation. Toon Link is on another side of the timeline (LET'S NOT START TIMELINE DEBATES, PLEASE). The same goes from Young/Adult Link in regards to Toon Link. Anyway, does Toon Link only have Wind Waker/Phantom Hourglass/Spirit Tracks stuff, or does he have Four Swords (& FS Adventures) and Minish Cap stuff as well?
Zero Suit Samus Vs. Snake
I'm not sure of the degree of protection the Zero Suit offers, as I've never played Metroid: Zero Mission, but that doesn't matter if Snake has a powerful gun. If he shoots Zero Suit Samus in the face, she's dead. If it's just a jumpsuit, he can shoot her pretty much anywhere. I'm pretty sure bullets go faster than the shots from ZSS's energy pistol.
EDIT: People posted while I posted. T_T
At any rate, if Snake's allow to bring a Metal Gear into this, then he moves up significantly. Not many people can survive being anywhere near a Nuclear Explosion.
Mr.Game & Watch Vs. R.O.B
Uh, wow. These are pretty much the worst characters. If ROB is just the Robotic Operating Buddy toy, then Game&Watch wins. If you let ROB have stuff from Mario Kart, then ROB wins.
Bowser wins (probably). In Super Mario Sunshine, Bowser is freaking huge. Combine his hugeness with all of his other techniques and Falco might not win.
Lucas wins, no contest. I know Yoshi throws eggs pretty hard and such, but
Lucas has quite the arsenal of PSI techniques, and PK Love is just as devestating as PSI Rockin.
Now moving on to the disputes about what to use, it's
much more simple to just restrict it to only the games. If you let anime/magna/comics come into play, some people get enormously more powerful, and there's always the cases of conflicting canons. For example, in the Sonic Comic, Sonic has a form called Ultra Sonic that lets him manipulate everything at a molecular level (along with the extreme speed/strength/invincibility), effectively making him able to kill everyone.
It's unessessary and makes everything more complicated and less fun.
@Kirby's invincibility: Yes, Kirby cannot be harmed by things he is
swallowing. So if Marth tries to stab Kirby in the mouth, it's not going to work. However, if you've played a Kirby game, you'll recognize the common Blade Knight who can easily harm Kirby with his sword.