The single mix of Please(Single Strings Version) is wonderful, complete new recording compared to the album. Get the long one.
Same with Walk On(UK single version). New performance, based off the live version.
Elevation (Tomb Raider Mix) is Elevation on steroids. Over the edge if you ask me.
Holy Joe (Garage Mix) is just what it sounds like. U2 is garage band form. Cracking rock track.
The Dirty Day(Bitter Kiss & Junk Day) mixes are quite good.
StuckIn a Moment (acoustic) is stunning. Get it.
I think that covers all the major variants.Stuff like The Fly, LNOE, EBTTRT have differences so minor to the album versions, they're not worth $.99.