U2 entered the 1990s determined to not be defined by their previous records. They looked for a fresh start with 1991’s Achtung Baby, casting aside the earnestness and any semblance of roots for an adventurous sprawl into the new decade. Each successive release pushed the boundaries until they’d felt they couldn’t go further and then, in a quick switchback, the group suddenly returned to their beginnings and classic U2 sound for 2000’s All That You Can’t Leave Behind. True to the band’s probing nature, this “Best Of” collection is more than just a collection of obvious hits (“One,” “Beautiful Day,” “Mysterious Ways”) but also a continuation of their sonic experimentalism, with new tracks that actually copyright in 2002 (“Electrical Storm,” “The Hands That Built America” the theme from Gangs of New York), obscurities (“Hold Me, Thrill Me, Kiss Me, Kill Me” from Batman & Robin), and remixes galore, including all the material from 1997’s Pop (“Discotheque,” “Staring at the Sun,” “Gone’). These reinventions make this less a “Greatest Hits” than another vantage point for even the hardcore U2 fan to take interest.