I know there are 51 Event Matches in Super Smash Bros. Melee and I have defeated events 1-30, but the other levels are not available. How do I get the additional event matches to become available?

I can't remember exactly, but I think you have to beat Classic Mode with the 14 original characters.

Actually to unlock the rest of the events you have to unlock both Falco and Luigi.

To unlock Falco I believe you have to beat the 100 man melee -- is there any character that makes this task not so difficult?

Donkey Kong makes it simple with his ground pounding move. I beat it pretty easily with Bowser and Captain falcon too.