Before we get started here is a breakdown by PPP of the 2nd goal of the Lightning on the Leafs. The screen caps are pretty awesome so it's worth a read.

As for videos, here is Martin St. Louis game tying goal:

I can't find a clip of JUST the Simon Gagne goal (at least without some ad for a twitter account plastered across it) so here is a video of the game highlights:

And here is a Simon Gagne interview on the game winning goal: