I still say that the entire TBOS album would work really well live, but that isn’t an option so it’s down to TXF and BNW. I’ll go for the former since I think that it would be really interesting seeing Bruce’s take on those songs (so long as he does butcher “Lord of the Flies” like on DotR) and I mean I love that album, so yeah.
IMO the more focused in one theme (moving towards a conceptual format) the better the album sounds being played in its entirity.
That's why my obvious choice is Seventh Son (well ... it's their only assumed conceptual album).
That's also why A Matter Of Life And Death sounded great played live in its entirity. Although it's not a conceptual album like Seventh Son, every single song is about war and confrontation between people in various perspectives. Here are other album that bears the same blueprint:
The X Factor: Every single song deals with dark feelings and thoughts, wether it's war, trauma, self doubt, anger or depression.
Somewhere In Time: While one can easily spot the concept of time on some songs (Caught Somewhere In Time, Wasted Years, Deja Vu), there's less explicit interpretation on other tracks. LOTLDR deals about the atrition and relativity of time and how it affects your will , on Heaven Can Wait there's the fear of departing our life and delaying of the absence of time (eternity), and SIASL also shows how sometimes a story that wasn't told can be perserved and revealed several years after. Then there's Alexander The Great, a little time travel to ancient Greece.
Killers: Almost every songs are about... well... assassins or tendencies to be one (only exceptions being Another Life, Purgatory and Drifter).
The Number Of The Beast: Here the main theme is ovious: evil, sin, damnation etc... On one hand we have songs that are focused on sin like lust (22 Accacia Avenue), vengeance (The Prisoner), rage (Gangland) or greed (Run To The Hills). On the other hand there's also some songs blattantly versing about evil and damnation like the title track, Children Of The Damned or Hallowed Be Thy Name.
Piece Of Mind: Many song here are about madness (Still Life, Flight Of Icarus), insane courage (Where Eagles Dare, The Trooper, Die With Your Boots On) or psychic powers (Revelations, To Tame A Land).
Powerslave: Well... every single lyric in this record seems converging to the sentence that gives name to the album: "slave to the power of death".
Anyway, AMOLAD. Actually, I would have wanted to see it live in its entirety even then, but I was fascinated by the missing bootlegs from the SIT tour (IIRC) and Loneliness being played in Belgrade and stuff and it influenced my pick.