Walk On! A good song to end on, quite cheery. Love it on Slane- you no its the last song without looking at the set list. Particularly with the " hallelluuuuuuja hallelluuuuja...." at the end of the song. Just has the sound and lyrics that best suits a final song for a concert- encouraging words.
40- "How long to sing this song" Good song but the crowd keeps singing that line and it could go on forever. But fitting lyrics tho.
I can't help falling in love with you- Sounds too sad.
I think 40 would be a perfect ending to the main set or the first encore. I sing "how long to sing this song" between every set anyway, when I'm waiting for U2 to come out again. I agree that 40 at the end kind of leaves people hanging on for more. "Walk On" has more finality to it. And it would be weird to play "Walk On' anywhere else besides the end.
Much as I loved the Australian Vertigo version of Kite, I think that could be incorportaed mid-show in future. Same goes for All I Want Is You (brilliant lead-in to Streets on Elevation) and Walk On (if it must be played,not a favourite of mine).
And with Vertigo Bono was just being literal about encore,which was fun, but not the best ending of a show I've heard.
In my opinion the best is Love is Blindness / Can't Help Falling in Love (must be these two together) - an amazing ending, full of emotion, and I don't know why they've never played Love is Blindness since (maybe because Edge is happy in his relationship with Morleigh now and I think this was written largely about his divorce?).
If they wanted to tack '40' on as a fade-out after this that wouldn't be bad....
