Ganon has the most satisfying spike. Not only is it incredibly effective, but it has a huge amount of freezeframes as though you just landed a sweetspotted attack, and then leaves your opponent looking electricuted to boot. Off hand, I can't think of any other spike that has either the delay or any elemental animation.
But yes, this thread is obviously designed to incite more argument. I just hope my post from the main thread doesn't get lost because of the argument getting hijacked over to here...
Edit: lol @ black shadow. I hope that typo was intentional because it's pretty funny. I say Bowser has the coolest looking meteor cancel in the game.. I mean, he pulls up into his shell and spins around while double jumps, and then when he follows it up with up-B he spins even more. Too bad it's not high enough to actually save him.. ever..