Marth, Link, and Samus all have really easy times with Giga-Bowser.
Marth - Jumping A as well as Counter (as mentioned) work wonders.
Link - Spin Attack, Up/Down Jumping A, and Bombs make short work of slow and stupid.
Samus - A combination of Missiles (non-homing versions) and charge shots make Giga-Bowser look pathetic.
He's not hard with any character really, but those three make it obscenely easy to win.







