They did have a great run of albums in the early-mid 80's, especially "Number of the Beast", "Piece of Mind" and "Powerslave". The "Live after Death" double cd from that period is really good too, and worth checking out.

Their last three albums with the six man lineup are quite good. One song you might like is "Dance of Death", its a pretty good ghost story, especially the live video from youtube.

Here is the link if you want. http://www.youtube.com/watch?v=6XIrHmm2fYI