:flame:
This is something that should be discussed on Roy_Own's Thread, once we've gotten the Pokemon Votes out of the way (We are currently on Entei vs Snorlax, but since that vote's pretty much over, we're about to move to another set).
But, since the Final Smash vote hasn't occured yet...
The best Final Smash has to be Falco's Landmaster. It flies faster so it gets better respawn kills than Fox's, and it lasts longer than Wolfs.
Bowser's, Diddy Kong's, Wario's, Yoshi's, Link's, Zelda's, Ganondorf's, Toon Link's, Fox's, Wolf's, Pikachu's, Snake's and Sonic's, amoung others, are also very good.
It seems that the best are the ones that transform the character (those also seem the most fair, since it actually takes skill to use them right, plus the other character can outkill them {Sonic's is only undodgeable when a Computer is using it}), or those that will produce instant kills (probably the cheaper ones, but still dodgeable) are the better Final Smashes.
Most of the rest, you can easily dodge out of and protect yourself (I've stood in the middle of Mario's on some stages, and been completely untouched, without pressing a button).
:flame: