The whole of season 1 is really Walt getting more and more bad ass. It's impressive because of the continuity from a person who has surrendered completely to obligation and guilt, to someone scary and assertive and altogether exciting. His sidekick Jesse meanwhile is a tragic figure, betrayed by his family. That episode literally gave me nightmares in which I let my children down as badly as Jesse's parents hurt him, and I was so pleased when I woke up and it wasn't true.
Here are two music videos which convey their two characters quite well - with some spoilers for seasons 1 and 2 if you care about that:
Scar Tissue - a Jesse vid
Bad to the Bone - a Walt vid
Here are two clips from the show
Jesse and Walt cook meth (season 1)
Walt is bad ass (season 2)
I guess this post is to try and sell the show to those who haven't watched it yet.