I will take the ending of The Mirror over the ending of Lie. The ending of The Mirror showed DT's ability to have a killer ending without feeling the need to solo or overplay (which is why it's not nearly as good now when played live since Rudess throws a wanky solo in it, which feels totally unnecessary), but the ending of Lie, which reprises The Mirror, is pretty great as well.
In the annals of great DT endings, it is hard to top Learning to Live, Metropolis, Scarred or A Change of Seasons, but The Mirror ending (of the proper Mirror song, not the reprise in Lie) would be in the next tier for me.