Nicely put by ickmusic:
If London Calling was the Clash’s masterpiece, Sandinista! - a three-LP, multi-genre assault on the senses (and the follow-up to London Calling) - was its stoned out red-headed stepchild. Thirty-six songs strong, Sandinista! was their chance to completely let loose and record whatever it is they felt like recording.
Read Rolling Stone's original review of Sandinista! - back in the day, before they'd put lame-os like Maroon 5 (ha!) on the cover.