It's the 35th anniversary of the release of The Clash's seminal third album, London Calling. But honestly, you don't need any excuse to re-listen to the entire thing, cover to cover.
The title track of London Calling is (rightly) the most famous — inspired by the Three Mile Island accident in Pennsylvania, it riffs off the famous BBC broadcasts to occupied countries in WWII, which always started with "This is London calling".
Recorded in a six-week period, working 18-hour days and often getting the songs in just a couple of takes, the album is often heralded as being the first 'post-punk' work — in other words, it's when punk (and The Clash) grew up. Regardless of which side of the musical nerdery you fall on, it's doubtless that London Calling is worthwhile listening.