Luigi and Ness in the 64 one, [Dr.] Mario, Ness, Game and Watch in Melee.
In Melee, Luigi doesn't jump forward with his ^+B attack, so it's useless as a third jump.
Ness was crazy powerful in N64, and in Melee he had a great moveset. PK Flash is hilarious to use on a huge group of people who don't notice you.
Jigglypuff is pretty sweet too--I use him and DK as jokes though
