This does not include Anime, people are way to passionate about that.
Otherwise the title pretty much says it all.
For me its Starbucks Piano Scene from Battlestar Galactica !
Unfortunately i could not find the real scene on youtube so here is a sorta version.
One of the few moments i got tears in my eyes while watching television, its not very powerful on its own but it ties the whole good part of the series together. When the music ramps up your mind just goes crazy.