Depends on how lazy i am at the time, if I let an intro play or just skip through it to the next song. I really don't feel strongly one way or another, right now of the top off my head, if I had to pick an intro that I remember that was actually worth remembering it would be either War of the Wrath by BG or Deliberately Limited Preliminary Prelude Period in Z by Helloween.
Bah, I can't stop sounding like a Helloween/Blind Guardian fanboy, oh well there are worse things to be accused of in this world I suppose.
I've just listened to these bands so much, it's the only thing that pops into my head instantly when I have to think about music that I really enjoyed.
I'm sure there are others I don't recall right away and only 5 days later when someone else mentions them I would be like "Oh yeah".