Chris plowing through the entire opposing ice hockey team (comprised of grade-schoolers, mind you) in brutal, epic slow-motion, culminating in him taking a slap shot on the open goal. The puck hits the crossbar, bounces back, and punches him in the teeth.
Afterwards, while strapped into a gurney at the top of a snowdrift and being loaded into the ambulance, Chris rocks himself loose, sending him screaming down the snowdrift and off a ramp, resulting in him flying through the air and landing face down on the ice.
Part three of the post-ice-hockey fiasco, Chris is strapped down in the ambulance en route to the hospital, gauze in his mouth preventing him from speaking. Right after Jamie gives Dusty her number, an oxygen tank falls off a shelf and nails Chris in the groin.
Chris: [muffled] THIS IS BULLSHIT!!
Any time Mike and Chris have a fight as a testament to their sibling rivalry.
Topped off by Christmas morning, when they look like they're about to start a fight, then exchange "I love you"s instead.
Chris's breakdown in the car after his day-date with Jamie. (2:38 here)
Mike accidentally tasering Samantha making her fall off a balcony. Best part is the Big "OMG!" done by one of the bystanders.
The twelve second exchange between Samantha and Mike in the bathroom. Mike knew Chris' location and Samantha wants to know. How does she accomplish this? She aggressively kisses it out of him.
It's further amusing considering these characters relationship builds to this culmination during the movie. It's obvious throughout that Mike's insanely hot for the massively randy (not towards Mike but his older brother whom she repulses) Samantha.
Twice Mike accepted Chris' offer to distract Samantha, with obvious intentions, and both results were disastrous.
Samantha later permits Mike's company and begins complaining about her sex-starvation, ignorant to her torturously arousing the teen. The conversation takes a sudden bizarre turn when Samantha tries seducing Mike. It's evedinet they're playing off the ego and crush of the respective other though Mike's comically unskilled at it:
Laughter ensured the next night. Chris got Mike's agreement to keep his whereabouts from Samantha, unaware she was awake. Samantha later trapped Mike in the bathroom and shoved him against the wall, demanding Chris' location but Mike refused. Undeterred, Samantha passionately French Kisses Mike who immediately complies.