I first became aware of Chvrches via the BBC Sound of 2013 list, which placed them 5th. It seems low - not just looking back, but also at the time, given that The Mother We Share had already been released.
That track clearly remains their most famous, but, three albums in, Clearest Blue is the strongest track for me. It just builds and builds and you think there's going to be an "everyone goes mad" moment - and then there's an "everyone goes mad" moment.
Although it doesn't share the structure and build of the single/album mix, it's definitely also worth checking out the Gryffin Remix - a different feel, but also pretty darned awesome.
2015 is quite new for a track to appear on this blog. I do actually tend to prefer to listen to new stuff, but for a song to appear on this list I want it to be something I've lived with for a while - something I know is going to stand the test of time. So, five-years will probably remain about the age threshold for songs that I list on this site.