I'd have to agree on the Maiden... although if the entire band died in the bus accident instead of just Cliff, Metallica would have a good chance. I suppose the same might be said of early Megadeth as well when they were all strung out on cocaine and heroin, but not after when Dave decided that it would be fun to get sodomized by jesus.
Iron Maiden. Specifically, original Eddie illustrations, a Steve Harris amp with his footprint on it, Adrian's red wristband, a tape of Bruce's longest rants, a box of strings broken by Janick, and Nicko's nose.
Iron Maiden. Specifically, The Number Of The Beast album. To quote Judas Priest (how ironic): "Well I said it before, and I'll say it again..", that album defines EVERYTHING to do with Metal. If it ain't on that album, it ain't Metal.