Either half of my namesake would be my top 2 choice (Hawk269 or the title track to Un. Fire). Perhaps more relistically, I'd love to hear Please, Ultraviolet, and Lemon. Oh yes, and Gloria and/or October.
Historically (Leg III v. Leg I):
Joshua Tree (Leg III): introduced One Tree Hill, dropped A Sort of Homecoming. Also added Electric Co, 11 O'Clock and Control on select dates (none of these three were in leg I, to my knowledge).
ZooTV (Leg III): introduced SBS and NYD, dropped WGRYWH? (except for a select few dates)
Zoomerang: introduced Lemon, Dirty Day, Crashed Car, dropped Desire, Ultraviolet, Bad, and Lovetown.
PopMart: introduced SBS (acoustic), Wake Up Dead Man, Desire (acoustic), and NYD and AIWIY (both played very sparingly on LegI). Dropped Miami, If God Will Send His Angels, and Do You Feel Loved (played sparingly on Leg I). Worth noting that Bad, MLK and Mothers of the Disappeared later appeared on Leg IV).
So it's reasonable to assume probably two major setlist switches will occur. Beyond that, probably not much more variation then we've already witnessed in the first 83 dates (which is a lot by U2 standards).
