By Mark Savage
Entertainment reporter, BBC News
Three of the world's most iconic rock groups - U2, Oasis and The Beatles - release greatest hits albums this week.
The battle for the top spot will be fiercely contested, but what can you expect from the three compilations?
THE BEATLES - LOVE
Who are they? Arguably the most influential rock group of all time, The Beatles were four young lads from Liverpool who changed the way music is played and recorded. You might have heard of them.
The Beatles were regular visitors to the BBC in the early 1960s
The album: Love features 37 Beatles songs in a brand-new continuous mix, put together by legendary producer George Martin. It is also the soundtrack to a Beatles-themed show by Cirque de Soleil.
Key tracks: There are almost too many to choose from, but the CD includes Yesterday, Blackbird and the not-at-all-about-drugs psychedelic anthem Lucy In The Sky With Diamonds.
Added value: For an extra £5, you get a bonus DVD with the entire album mixed in surround sound.
The press release: "A vivid, intimate and powerful entertainment experience."
In 1996, the three remaining Beatles compiled the Anthology CDs
Previous Greatest Hits: This is the eighth album to bring together the Beatles' hits - or the 11th if you include the Anthology series, which compiled out-takes and demos.
Sales record: The Beatles' last greatest hits album, 1, sold 2.7m copies in the UK.
Random Beatles quote: "We sold out, you know. The music was dead before we even went on a theatre tour of Britain." (John Lennon in Rolling Stone, 1970)
OASIS - STOP THE CLOCKS
Who are they? The Gallagher brothers, Liam and Noel, plus an ever-changing group of backing musicians, who go by names such as Gem and Bonehead.
Oasis were a key act of the Britpop era
The album: Stop The Clocks is a double album stuffed to the gills with the songs that helped define Britpop. They were hand-picked by the band (Noel), which means you get album tracks and b-sides alongside the singles.
Key tracks: Jukebox classics Don't Look Back in Anger and Wonderwall will be sung at closing time until the day you die. But some of Oasis' bigger hits, including Whatever and Roll With It, are missing.
Added value: A limited edition 3-disc edition is also available, containing a DVD with live performances and an interview with the Gallaghers. The Japanese version of the album features two extra tracks.
The press release: "This is not a full stop, but merely a time out; a dream set list, and a chance for the world to review the immense contribution that Oasis have made and continue to make to rock'n'roll."
Oasis played a 10-month world tour to support their last album
Previous Greatest Hits: Oasis say they will never release a true Greatest Hits album until they split up (this counts as a Best Of, apparently), but they do have a compilation of b-sides, called The Masterplan.
Sales record: The band's second album, (What's The Story) Morning Glory, has sold more than 4.3m copies, making it the third biggest-selling album ever in the UK.
Random Oasis quote: "I wasn't taught music by anybody. I didn't learn music at school. I can't play the piano." (Noel Gallagher in The Times, 2001)
U2 - 18 SINGLES
Who are they? The Irish four-piece who stole the show at Live Aid, reinvented stadium rock, and put an end to poverty (tbc).
The band has won more Grammy awards than any other act
The album: As the title suggests, 18 Singles features 18 of U2's biggest singles from the last 20 years. Two of the songs have been specially recorded for the collection.
Key tracks: The world's most heart-rending ballad, One, and the world's second most heart-rending ballad, With Or Without You.
Added value: Brilliantly, the UK version of the CD has a bonus track - which instantly renders the album's title nonsensical. A special edition comes with a 10-track live DVD recorded in Milan.
The press release: "U2 18 Singles is the first single-disc collection to span the band's 26-year career."
U2 are currently finishing their world tour in Australia
Previous Greatest Hits: Two earlier volumes of U2's Greatest Hits cover the band's singles from the 1980s and 1990s. Completists can also buy every track the band have ever recorded - and there are 446 of them - on iTunes for the bargain basement price of £120.
Sales record: U2's previous greatest hits compilations have sold more than 2m copies.
Random U2 quote: "Edge acquired his echo unit and that changed everything. It was punk rock with a symphony - suddenly you're in outer space instead of suburbia." (Bono in U2 by U2, 2006)