Peach vs. Kirby
Kirby is just so much better, lezbe honest. The creator of the game also created Kirby (if I'm not mistaken) so Kirby obviously gets better treatment that makes him a much better character.
Not really. Kirby was only good in Smash 64. He was complete crap in Melee and very mediocre in Brawl. Peach is one of best characters in Melee, and at least better than Kirby in Brawl.
Falco vs Samus
I love Samus, especially in Melee. But overall Falco is one of the few character who's been consistently at the top of his game in each games he debuted in. He has a much versatile repertoire and tends to have incredible control over the air and a great one in the ground. (Opposite of Fox, basically) Although unlike Fox, and many other characters, particularly Samus, he can be played in many different playstyles. He's great at pressuring other characters for those who like to stay constantly on the opponent's face. He's a great juggler making him effetive for combo lovers. He has great control over the air, as mentioned, making him suitable for air-oriented players (such as myself) too. He also can be played as a zoner, since he has one of the best projectiles.
Sonic vs
Luigi
I love Sonic but he's
awful. Better than Luigi in Brawl as a character to play, mind you, but he has one of the worst movesets overall. Amazing how Snake gets one of the best moveset, if not THE best, of all the Smash series with tons of cool references to his games (actually how did he get knocked out? I blame all of you!), and then Sonic gets the undisputed worst moveset in the game. He was clearly a last minute addition. Luigi at least is fun.
Sonic is just so bad even Sonic players find him to be poorly designed. He literally only has his speed, making him only suitable for time outs. Knocking out? Yeah, with those **** smash attacks he has, you'll probably be start spamming unreliable back airs.
Peach vs Kirby
Frankly I find Kirby to be yawningly boring to play. Peach is pretty fun, and a much better character to boot. >_>