The final McLovin+Cops scene. They do donuts in their patrol car, crash it, then set the thing on fire. As if that's not enough, Drunk!Slater hands McLovin his pistol. McLovin, who has never fired a gun before, proceeds to unload an entire clip into it, gangster-style, screaming his head off.
Before that, they were willing to fake an arrest for him to up his reputation.
It may not have seem that way to him but Evan refusing to take advantage of a very horny but still very drunk Becca is a moment of awesome.
Slater whacking Jesse (the asshole with the mullet) across the face with his nightstick after he spits on him. Serves as indirect payback for his mockery of Evan and Seth at the beginning of the film.