Wiimote & nunchuck is enough for most people. It's possible the GC may have a technical advantage (I have no clue), but for the vast majority it won't matter. Set down on the D-pad to jump, and you'll do fine.

Personally I've played it with nothing but the Wiimote/nunchuck combo, because they're more readily availible than GC controllers among my friends. Also, I only have one wavebird, and I really dislike using wired controllers (potential risk of knocking the Wii down if one trips on it).

Gamecube. Just used to it. Didn't want to change when I had been playing SSBM up til the release of SSBB haha.

gamecube, i got used to melee

gc, u can map the controls really well. none of my friends (except one due to lack of controllers once) have even thought about using anything but.

just Wii-remote, it's more convenient

Wii Remote + Nunchuck of course.

wii mote

GC controller Got a gc controller and a cord extender hooked up makes life easier.

Wiimote and nunchuck, it took a lil to get used but its great, I kinda forced myself to use it cuz i sit about 4m from the tv and i dont have the wavebird. Since then i cant use the GC controller anymore.

I didn't play Melee for more than a couple hours several years ago, but I still feel GC > Classic > Wiimote & 'Chuck. Having an actual pad just works well for fighters, IMO.

That being said, they're all perfectly serviceable, and Wiimote & 'Chuck do have the advantage of being wireless with the comfort of split design.