Well, looking at the staples in U2's setlist, I'd like to suggest several things:
From BOY there's one tune, that comes first and survives whole tours as the most played song from the 1st and 2nd album album: "I Will Follow". Though I like it - if played in full version, with a hard and fast pace - I still hope there will be more variety reagrding this era. There are still tunes that might be rediscovered ("Twilight", "Tomorrow", "I Fall Down" or "October"). Am I crazy? Just think about somebody before 2005 with the prophecy, that "The Electric Co." would be kind of a regular during the next U2 tour ...
From WAR I do hope, that the classics "Sunday Bloody Sunday" and "New Year' Day" might change from every night regulars to tunes, that will be played occasionally in the sets, maybe not together in one show. By the way, these tunes are not tired at all: Just listen to the "Rock The Casbah"-versions, especially on the last leg and take N.Y.D. from Melbourne's 1st night - wow!
From THE UNFORGETTABLE FIRE it is now really time to get the brilliant title track back in the setlists plus a more the welcome return of a well rehearsed version of "A Sort Of Homecoming". Yes, "Pride" is more popular. Yes, "Pride" is an important political statement. Yes, "Pride" is a #1 single - but this tune doesn't deserve to be cut off before the ending and be converted to a crowd pleaser "oh-oh-oh-oh" chorus a la football stadium atmosphere. Before doing even worse to "Pride" put it in the rotating slots like the WAR classics - and play it complete, when you're up for the song.
From THE JOSHUA TREE we've got the first album side as a staple in U2's setlists (maybe "Running To Stand Still" should be excluded from this theory...). From these tunes really only "Streets" stands the test of time. This should be the ONLY regular in the sets from the 80ies. It's the live moment in perfection - for 1st timers and more experienced afficionados alltogether. Regarding "Found" it has to be played from time to time - with feeling & spirit. "With Or Without You" is in the same dilemma as "Pride" - it stands more and more NOT for the brilliant piece of music and lyrics, but for a big "oh-oh-oh-oh"-football chorus as an ending. Nope, it's a bitter tune - play it like that, including the often missing lost verse plus fitting snippets. Yes, love will tear us apart - again! "Bullet the Blue Sky" has been cut short, too on the last tour. Give it a rest and rediscover other tunes as anti-war statements. Why not "Mothers Of The Disappeared" from the same album or "God Part II" from RATTLE AND HUM.
From ACHTUNG BABY there is of course one tune: "One". And yes, this tune has to be played, too, every night. But you can change the arrangement and stop the routine with that: Play it full electric one evening, the next in an acoustic arrangement a la Thalia Theater Hamburg in the ZOO TV times. Or also more stripped down, as it is the basis of the great '95 Modena version by Bono & The Edge.
There is one last staple I do see coming: "Beautiful Day". I don't need it every night, too - so just put in on the rotating slots of the setlists. And then: Rock it!