I can think of one person who I "brought back" to U2 after he fell out of love with them in the 90s. He's an internet buddy who had bought a bootleg of my first (and only) U2 concert and was going to send it to me for Christmas. Then he found out I'd already gotten a copy of the boot for myself.
So I told him to keep the one he'd gotten and enjoy it. So he does -- he apparently cranked up his sound system to 11 and listened to the entire thing in one sitting, drink in hand. His impressions of the show:
- He referred to the opera part of Miss Sarajevo as "jaw-dropping."
- He was pleasantly surprised with how much he liked (loved, even) the acoustic Stuck in a Moment, given that he'd hated the studio version. He also couldn't believe that he liked Beautiful Day as much as he did.
- He was really impressed with Bullet. He had no idea that it's been a live staple since '87.
Keep in mind, his musical tastes lend themselves more to hard rock and simple crunchy riffs, so it was really interesting to get his take on a lot of songs he'd never heard before. I sent him a "bootleg of the day" for a few months and convinced him that I'd get him liking at least one song each off of Pop and Zooropa. So far, I've succeeded. He
loved LNOE and dug Please and Wake Up Dead Man, so mission accomplished, I guess. He's also gotten five versions of All I Want is You (really, I've never heard a bad one) and several Still Haven't Founds, because he loves that song.
Other interesting impressions I got from him: he didn't care for Gone all that much, which surprised me. He didn't like Kite at first (I sent him the Slane Castle version), but the song popped up on his "random play" feature one day and apparently hit him in just right mood -- now he loves it. His favorite of all of them was probably HMTMKMKM from Popmart Leeds. Since he hadn't heard the studio version in nearly a decade, I sent that too. He referred to it as "the greatest James Bond theme song to never actually become a James Bond theme song, ever." Heh. And his favorite All I Want Is You was not a Lovetown version, but the shortened, stripped down version from Popmart Leeds. According to him, it had "everything I like about the song and nothing that I didn't." Bono's version of "That's Life" was also a big hit, as was an acoustic TGBHF.
Edited to add: the studio version of In A Little While absolutely made his week (if I had to guess, I'd say this would be his current favorite U2 song, which shocked the hell out of me. I wasn't sure if he'd like it.) So I sent him the Vegas version with Brandon Flowers singing on it, and he grudgingly gained some respect for the guy after that.
So, 'twas a successful mission.
My wife OD'd on U2 when we first started going out and now wont let me play them around her anymore... 
I didn't become a fan until years later, after she'd stopped trying.
