Having the Complete Collection of AOE3 (up until DE3 that is) available on GOG would be great. The game is not available anywhere else at the moment, and should be preserved in its original and remake state for the sake of the community and ease of access.
Now as for memories, I transitioned to this game in-between playing AOM, and I always appreciated its fantastic art style and depth of gameplay. My dad and I played through this game a lot too and I loved breaking his base with an army of canons. ;)