Many great moments make this episode one of the best of the 1st season!
One thing that South Park has always done well is to take many, many random elements and put them together into a great story. This episode is a great example.
On a field trip, the boys discover a triangle, which is actually one small piece of Barbara Streisand's Take-over-the-world puzzle.
Every moment of this episode is completely ridiculous, but it's perfect. Leonard Maltin, Sidney Poitier, and Robert Smith of the Cure all make appearances as Godzilla-style monsters, taking on the Mecha-Streisand.
This episode is a parody of a variety of sources, but mostly it's a parody of Godzilla. Complete with a singing Japanese man, all of the random elements come together to make a great episode.