For shock and awe it has to be normal tv getting interrupted for 9/11 and, having thought I'd never see anything worse than that, turning on the tv Boxing Day 2004 and seeing the scale of the unimaginable devestation caused by the tsunami gradually unfolding (I don't think anything on tv has ever made me cry so much)
In contrast one of the funniest...at least it was hysterical to an 8yo in 1969
http://www.youtube.com/watch?v=N_Cj2TtFd_E
The greatest by far is, without question, watching Ireland win their first Grand Slam since 1948...I'll die happy just knowing I lived long enough to see that...only an RWC win could come close to topping it.
Regards
JAS