No U2 playlist can be complete without these 25 essential songs

From 1993's Zooropa, U2 was full-blown in its experimental stage and "Lemon" seriously expanded the band's audience — for better or worse. Spanning nearly seven minutes in its album form, "Lemon" is one of U2's longest, and certainly most innovative, tracks. It tread beyond the experimental/electronica sound and into retro disco and dance. Various mixes of the tune were released, which was a sign that the band was comfortable doing whatever it wanted.

More from Zooropa. "Numb" features The Edge providing monotone, almost spoken word-like vocals. Bono offers some falsetto backing vocals on a track that is thoroughly creative (it was co-produced by the renowned Flood and filled with samples) and criminally underrated within the annals of U2's legacy. While the Zooropa album is not for everybody, "Numb" is definitely one track that to appreciate.

War, U2's third studio record from 1983, unveiled an edgy, more aggressive approach from the band — both musically and lyrically. It was the band's first true political album. "40" is the 2-minute, 35-second closing number on War. Now, "40" isn't as raw and forceful as some of the more celebrated tracks from War, but it's actually a rather hopeful ending to an album that is far from bright and cheery.

More from War. Musically, this is one of U2's best compositions, and it has stood up quite well over time. From Adam Clayton's stout opening baseline to more relentless guitar fretting courtesy of the The Edge, there's a definite punk feel to a song — and album — that was a major player in alternative rock turning the corner towards a more mainstream audience. Plus, who doesn't love a music video where band members perform in parkas?

Following the band's experimental run and a rather lukewarm reception to 1997's Pop, U2 reverted back to a more straight-forward alternative rock sound with All That You Can't Leave Behind (2000). A sound and approach that harkened back to Achtung Baby, or even earlier, and more accessible to mainstream listeners. "Elevation" is one of the more upbeat numbers on the album, a live favorite, which won the Grammy Award for Best Rock Performance by a Duo or Group with Vocal.

The lead single from 1988's live/studio Rattle and Hum album, the up-tempo "Desire" was an immediate hit. It peaked at No. 3 on the Billboard Hot 100 in the United States, but was U2's first No. 1 single in the United Kingdom. It also took home the Grammy Award for Best Rock Performance by a Duo or Group with Vocal. Rattle and Hum had an undeniable blues feel and "Desire," with a little rockabilly thrown in for good measure, certainly fit the bill

Another big hit from All That You Can't Leave Behind. "Walk On," one of those songs we love that features the title of the album it's from in the lyrics, won Record of the Year at the Grammys in 2002. The tune, lyrically inspired by the story of Burmese diplomat Aung San Suu Kyi, features The Edge putting down his trusty Fender Stratocaster for a dance with Mr. Les Paul. It all works, at its schlocky and mainstream best.

From the 1981 album of the same name, and U2's second studio effort. After all these years, "October" remains one of U2's most unique tracks. The slow-paced, piano-driven piece is essentially an instrumental that checks in at just under 2 1/2 minutes, but it's undeniably impactful. Obviously known as one of rock's great guitar players, The Edge shines with his simple, yet somewhat haunting piano work that's the backbone of this early U2 classic.

The Grammy Award-winning Achtung Baby, U2's 1991 release, was a rather stark departure from The Joshua Tree and Rattle and Hum. The album had a more alternative feel, mixed in with some pop, electronica and experimental offerings. It all opened the door for the band to take even more chances with its music down the road. "Until the End of the World," touching on a neo-Jesus-and-Judas relationship, is a prime example of U2's new approach, but still has that straight-forward rock sensibility.  

The Rattle and Hum closer harkens back, in some ways, to U2's stuff from earlier in the 1980s. Of course, with more polish and better production. Complete with its slower pace and endearing Bono vocals, "All I Want Is You" didn't enjoy initial chart success in the United States, but it had a rebirth after its inclusion on the soundtrack of the 1994 Winona Ryder vehicle Reality Bites. Also, a stellar cover of the tune by Irish girl band Bellefire is worth a listen.

A truly underappreciated deep cut from Achtung Baby. It's one of U2's more personal songs. Reportedly, it was at least partially inspired by the demise of The Edge's separation from his wife at the time. The pace, passion and emotion of the song allows it to fit in with anything else on the critically acclaimed album. It's good enough to appeal to any faction of the group's fan base, which might have been a little confused about its allegiance back then.

The Joshua Tree (1987) is one of those rock records that will never go out of style. It's easily accessible to fans of just about any genre within the overall rock and roll framework. A collective storyline of the real, imagined or expected America, the impeccably composed, structured and produced album sold more than 28 million copies. To mainstream audiences, "With or Without You" is the centerpiece. It was U2's first No. 1 song on the Billboard Hot 100 and is regarded as one the greatest overall tunes of the 1980s.

Going back to U2's 1980 debut Boy, "I Will Follow" is still one of U2's most popular songs — a number that is played live more regularly than not through the decades. Bono reportedly wrote the song in tribute to his mother, who died when he was a young teenager. It was also our introduction to the budding brilliance of a young guitarist known as The Edge. "I Will Follow" reached No. 81 on Billboard's Hot 100.

The Joshua Tree record might have turned U2 into international rock superstars, but War and certainly 1984's The Unforgettable Fire laid the groundwork for that to happen. With renowned producers Brian Eno and Daniel Lanois in tow, the latter reached No. 12 on the Billboard 200 albums chart. Its opener, "A Sort of Homecoming," is a perfect example of the more polished, less raw sound that allowed mainstream audiences to warm up to U2, while not completely alienating the longtime supporters of the band. 

There's an almost subtle orchestral feel to the title track to U2's fourth studio album. The tune is heavy on melodies and known for The Edge's creative tuning of his guitar on the piece. It's a song that, while certainly plays a prominent part in the band's legacy, actually tends to get overshadowed because of the more mainstream hits from the album that we'll get to shortly. It's always a treat when the group decides to play this song live.

The War opener and one of the most recognized rock songs of all time. Unabashed and straight forward, it was U2's first truly political song, focusing on the 1972 Bloody Sunday incident in the Northern Ireland city of Derry. From its militaristic drumming to more memorable harmonies, "Sunday Bloody Sunday" turned U2 into a band with a purpose. It was a top-10 hit (Billboard's Top Tracks chart) and arguably remains the signature song within the band's legacy. 

All That You Can't Leave Behind returned U2 to international musical dominance and retained its place among the giant entertainment acts in the world. The it-isn't-as-bad-as-it-seems" "Beautiful Day" got that ball rolling as the first single from the record and never looked back. The song was a top-25 hit in the U.S. and cleaned up at the Grammys, winning for Song of the Year, Record of the Year, and Best Rock Performance by a Duo or Group with Vocal.

There is much going on within the confines of Achtung Baby. "Mysterious Ways," however, delivers enough of that dependable guitar work from The Edge, while channeling the alternative pop sound that was about to break big on the mainstream music scene. In the U.S., "Mysterious Ways" reached as high as No. 9 on Billboard's Hot 100 and was a consistent presence on MTV — complete with some nifty Bono dance moves and filmed with trippy camera effects.

A true hidden gem from Rattle and Hum. The Edge wrote the lyrics and sings lead on a track about John Boyle O'Reilly, an Irishman who led an uprising in 1864, following the Great Famine. He was then banished to the prison state of Australia (aka Van Diemen's Land). The Edge doesn't often get the chance to show off his vocal chops, and his almost arid-sounding voice might not be for everyone, but it works here.

There are plenty of longtime, die-hard U2 fans who can live without hearing "One" again. Yes, it was overplayed throughout the 1990s on radio and MTV, and it grew into a classic-rock staple. Still, the song, which as legend has it bloomed out of the fractured relationship within the band's collective during the recording of Achtung Baby, earned a life of its own. It continues to be used as an anthem by the group to promote causes involving human rights and social justice. 

Perhaps Adam Clayton doesn't get enough credit for his work on the bass guitar. One of his best performances comes on this popular lead single from War. Clayton's baseline is a major part of the song's foundation and isn't entirely overshadowed by The Edge's stellar guitar playing that steers the tune toward the greatness it's achieved in the annals of alternative and mainstream rock. "New Year's Day" failed to crack the top 50 on Billboard's Hot 100 upon its release, but it has long been a highlight of U2's legacy.

Out of the gate from its September 1984 release as the lead single off The Unforgettable Fire, "Pride" did not necessarily wow critics. However, Bono's musical tribute to Martin Luther King Jr. eventually became a commercial success and reached No. 33 on Billboard's Hot 100. It's one of U2's signature tunes and a defining moment in the band's legacy. To no surprise, it's traditionally one of the highlights of U2's expansive live shows.

The heroin-themed "Bad" can be found in decent studio form on The Unforgettable Fire. However, it's the exceptionally emotional, eight-minute live version from 1985's Wide Awake in America EP that gained widespread acclaim. It became a favorite of fans and radio stations alike, and it showcased the brilliance of the band in a live setting. The latter was undeniably reinforced with its memorable Live Aid performance of Bad in '85, which featured a mullet-clad Bono dancing in front of the stage with a female member of the crowd and a tribute to the Rolling Stones and Lou Reed.

It's easy to listen to The Joshua Tree in its entirety and not feel the need to fast forward at any point. Even causal mainstream and alternative rock fans know about the hits for the record, but one of the great deep cuts of all time can be found on the album. "Red Hill Mining Town" chronicles the 1984 union mineworkers strike in Great Britain, but never made it out as a single. Though, that was slated to be the case. In the end, the band felt the track was "over-produced" and didn't like the way the video turned out. Still, it's one of Bono's great vocal moments and a song that definitely deserves more sustained praise.

One of the great opening tracks to an album of all time, and perhaps that's because the song features one of rock's best introductory riffs. Courtesy of The Edge's delayed, broken chord romp that builds and builds until Bono proclaims "I want to run, I want to hide." Even better than the song itself is the Grammy Award-winning music video filmed on a rooftop in Los Angeles, which features a shirtless Adam Clayton and throngs of people below — an example of just how big the band had become. The tune peaked at No. 13 on Billboard's Hot 100.