Revenge of the Nerds
(1984)

After the nerd's house is badly vandalized by the Alpha Betas, Gilbert (Anthony Edwards) goes to the homecoming rally to address the crowd.  He's thrown into a fountain and almost beaten up before the Tri-Lamb alumni steps in and allows him to use the microphone.  Gilbert encouages everyone who was ever picked on to stand up and join them to show they are actually the majority, and the beautiful people are outnumbered. 
 
Lewis (Robert Carradine) ends up with Betty (Julia Montgomery). 

Thanks DrummerBrian!