Are you the 
>! Mario theme song?

Even your mother may have heard of me, I'm as iconic as who I represent.
>! It's an iconic theme song, and so is Mario.

Ecstasy will fill your body with glee, as you start and when my sounds I present.
>! The sounds make you happy because they're the soundtrack of my childhood too.

Except those who never knew the joy, of jumping through clouds or exploring underground.
>! Part of the Mario games, you wouldn't know the theme song if you didn't play.

Celebrated by most fanboys, they may even cry and cheer when they hear my sound.
>! Same as above, I had friends who learned this on the piano (and yes, so did I, at one point ;P).

Especially when you show them my original form,
>! Especially the original Mario theme song with all of its metallic sounding glory.

Great waves of nerds and fans alike may arise and storm.
>! Everybody knows the theme song!

The secret hint is
>! The acrostic, EEE CEG, the opening 6 notes to the theme song.

And yes, that is indeed the sound of my childhood!! :D