Another possible contender from that song would be the totally random shouts of "GERMANEEEEEEE!" later in the song. Also the goofy-ass grin on Paul's face as he's having sex with 'his' model.
"Blitzkrieg mit dem Fleischgewehr" and "steck Bratwurst in dein Sauerkraut" are also contenders.
Hell the entire video can be counted as one, being a ridiculous, over the top parody of porn stereotypes, complete with goofy faces and cheesy lyrics.
A couple of scenes from the "Amerika" video - one where the band members are holding hands and dancing around the American flag, and the scene immediately after when they're all standing in a cheerleader pyramid. All while wearing space suits. On the moon.
The "simulated sodomy" at "Bück Dich" stage show.
The "Bück Dich" stage show is taken Up to Eleven in the Made in Germany tour. It starts off with Schneider abusing the other band members and ends with Till squirting his dildo right into Schneider's face.
Richard, Ollie, Flake and Schneider are all thinking about how they would have killed Till...then it cuts to what Paul's thinking about...
During the fight scene, keep an eye on Ollie and Schneider. While Richard and Paul are going nuts and beating the crap out of each other the other two are just sort of weakly shoving each other around.
Also, "Das Kleines Ton", a video of Rammstein's Live aus Berlin performance... set to the Mexican cumbia song "El Sonidito", and perfectly synchronized with the band's moves, to bout!