I played Melee a lot, and if I'm not playing it I'm watching pink fights. select captain falcon with his pink costume, luigi with his red/pink costume, fox with his purple costume and pink yoshi. set them all to cpu lvl 9, enable only pokeballs and super mushrooms with very high appearance rate, set 20 lives and damage ratio to 2.0 and select onett or yoshi's island as stage, enjoy.
I also played the shit out of 64, used Mario as my main and played well with Fox, Jigglypuff and DK. now I picked Pikachu and Ness too.
on Melee I liked to use Marth or Jigglypuff, later I picked Ness and Pikachu to add variety. but used nearly everyone except Bowser(too slow), Mewtwo(too weird) and Mr. G&W(weird too).
I didn't liked Brawl very much but still played it because of the popularity. there I mained Pikachu and Ness with Lucas as an alternative. I liked to use King Dedede(I like the character) but he was tricky to use. then I picked Ike to see why was he popular and he is a beast, easy modo made smash fighter.
as a fun fact I was once in a anime/gaming event and there was the infallible smash brawl, I picked the controller choose Pikachu, moped the floor with the guys that where supposed to play the tourney and the continued my path to see the rest of the floor.
In smash 4 I main King Dedede(thanks mashpotato samurai for the buff) and Lucina and try to git gud with Duck Hunt. other fighters I play well are Pikachu, Ness, Link, Mii Gunner(Homuhomu from Madoka Magica), Marth(doh), Roy(doh x2) and Ike.