ISHFWILF - represents a spiritual connection with music itself, able to transcend to something higher
One - symbol of unity and harmony as a band, which allowed them to come up with a timeless gem
Beautiful Day - an energetic classic that embodies musical maturation, being not just a commercial success and a huge hit, but proof that their music has soul
Funnily enough, these 3 songs come from their 3 best albums IMHO, covering the first 3 decades of their career.
Also, it's interesting to see that many "war horses" are showing up in the answers. I guess we (hardcore fans) get that fatigue feeling from songs such as Vertigo, Beautiful Day, One, etc., because of how closely we follow the band's performances and how often we get to listen to those songs, but they undeniably have their worth, even for us, let alone for the casuals, and nothing wrong with being a casual fan, as it's the case for me with many other bands.
That reminds me of the JT30 tour, when at first I was glad that Vertigo had been left off the setlist cause I felt like it didn't fit thematically with the tour, then I got bothered when they added it in the set a few concerts down the road, and then when I attended the Miami concert and they closed the night with Vertigo I had a blast and experienced one of the best vibes ever at the end of a concert, so yeah, that served to shut my mouth with style
Sunday Bloody Sunday (the classic early U2 song, will live forever)
Where the Streets Have no Name ("the" live anthem)
One (profound ballad with some of that great 90s sound).
