I seriously find the choice difficult, simply because of the big amount of good songs made in the nineties. Can't help it that others don't find the quality/atmosphere/power/energy....fill in here... in all those tracks.
Apart from maybe two or three exceptions, I find the lesser tracks from this era at least as good and in some cases even better than the lesser tracks on (esp.) Dance of Death and Brave New World.
Really, my Maiden collection would feel empty without e.g. "Afraid to Shoot Strangers", "Sign of the Cross", "The Unbeliever", "Lightning Strikes Twice", "Fates Warning", "No Prayer For The Dying", "Mother Russia", "Judas Be My Guide", "Childhood's End", "The Fugitive", "Public Enema Number One", "The Clansman", "Be Quick Or Be Dead", "Fear of the Dark", "Man On The Edge", "Fortunes of War", "2 AM", "The Educated Fool", "Tailgunner", "Blood On The World's Hands", "Futureal", the list goes on..... Can you imagine a setlist like that? Holy cow! Well, those songs mean as much to me as all the tracks you guys have mentioned, or in some cases even more.
I admit: AMOLAD is full of good tracks (apart from the opener), Brave New World has about 6 tracks of the same level, but Dance of Death?
Dance of Death has in my humble opinion only 3 memorable tracks, each by a different guitarist. The title track by Janick, Rainmaker by Dave and Paschendale by Adrian. The rest consists out of weaker, more simple and at times monotonuous, repetitive and uninspired material, with hardly any nice catching melodies.
So I guess I'll vote for these 4 nineties albums, instead of only 2 good ones.