like pianobabe, I like big orchestral climaxes like the first couple minutes of Wagner's Tannhauser, or Liszt's Les Preludes.
However, for some reason I really like key changes that happen at a single point to break into a rustic folk dance type of thing. For example, I dont think much of Hungarian Rhapsody No. 11, but I listen to it just for that last page which is so euphoric and fun to listen to. Something similar happens in Donizetti's "La Marche Pour Le Sultan Abdul Medjid-Khan". Just all of a sudden, a childish very playful tune jumps out and tickles my eardrums.
Also, the right kind of noise with a catchy rhythm really makes me smile. have a listen to Liszt's paraphrase on Gaudeamus-igitur. haha its just a bunch of garbage, but it does something to me for some reason.