I kinda want to play, too, but I'm--yay, Triforce Slash by Link! Final Smash pwns all!-- only good at Marth, really, and even then his attacks aren't actually that powerful. Meta Knight's strong, but it's a little hard to control his Mach Tornado. That's why I'm training up with Ike... even if he's slow, his attacks have enough power to KO an opponent after only a few blows. Maybe tomorrow I'll try it out.
I always thought Samus was a robot until I saw her Final Smash... then her suit was destroyed and the completely human ZERO SUIT SAMUS appeared. Yaaay.
You know what the worst Final Smashes are? Yoshi's for sure... he grows wings and flies around. Freeeeakin awesome, Yoshi, freakin awesome... The Pokémon Trainer's Final Smash (called Triple Finish) is plenty powerful but he can only shoot it in one direction. Meta Knight's offers an instant KO, except you have to be practically right next to the opponent since its range isn't very good.
Marth's Final Smash is strong but dangerous, since it's a dash attack and therefore if you miss you'll most likely fall off the stage. Ness and Lucas have pretty much the same Final Smash, basically a meteor shower, which should be powerful but honestly it seems to hit the stage everywhere BUT where your opponent is. Oh! Luigi's sucks... that's all I'm gonna say.
Link and Ike have similar Final Smashes (Triforce Slash and Great Aether respectively), just like how the Pokémon Trainer, Zelda, and Samus have the same... just a giant beam (arrow, in Zelda's case) fired in a single direction and obliterating anyone in the way.
Jigglypuff has the awesomest Final Smash ever, though... especially if you play on Final Destination. It literally puffs up and takes up the entire stage, pushing off anyone else and letting them fall to their DOOM. Epic.
Pikachu and Sonic have practically the same concept for their Final Smashes... Pikachu uses Volt Tackle and flies all over the screen as a giant ball of electricity, and Sonic transforms into Super Sonic and flies all over the screen as a golden hedgehog. Generally that should be powerful and cool, but the setback to their Final Smashes are that they become hard to control... so you end up using all your time trying to get them to where the opponent is while said opponent just screws with you and jumps out of the way.
I don't really get why Pit is so popular... I mean, sure, he's cool and everything but his Final Smash- Palutena's Army- isn't that good, and his only worthwhile attack involves him spinning his bow around and around. But... you know, he's a freaking angel so whatever.
I'm still bored so I'm just gonna go now. Not that you care since I don't think you even read this.