I only discovered this band recently, but already I love them. They're quite similar to Stornoway, in that they often use unusual instruments in their songs such as metal radiator guards and steam engines (well according to wikipedia anyway!).
Hope Hung High
Johnny Flynn and the Sussex Wit
Not to sure if they're actually from London (as Johnny Flynn himself is from Hampshire) but again Wikipedia says they are so I'm just gonna roll with that. They're a bit different to the music I usually listen to, as they're quite folky. If you're looking for a comparison, I guess they're quite similar to Mumford and Sons (who for the record I think are overrated). But Johnny Flynn and the Sussex Wit in my opinion, are really good, so I recommend that you give them a listen.
Tickle Me Pink
Noah and the Whale
I'm guessing most of you will have heard Noah and the Whale before, or at least recognise some of their songs. Who can forget '5 Years Time', the insanely catchy song that was played on the radio and in shops constantly back in 2008?! Since then they've released two more albums, which are both very different to their debut album, 'Peaceful, The World Lays Me Down' which is always a good thing. My only criticism would be that often the songs from each album sound quite similar to others on that album.
5 Years Time
Discovered them via the great invention that is 'WatchListenTell' Originally it was the name that attracted me to them, perhaps because I like shiny things (!). But since listening to their music I love them. They've already played on Jools Holland, and have supported Blur at a concert in Hyde Park, so they're definitely going places!
They provide the soundtrack to my childhood as their first album was released back in 2000 when I was just a wee youngster. Each song just has so many memories, cheesy as it sounds! Plus I love that they're one of the few bands out there that relies so heavily on the piano, which might irritate some people, but for me there's nothing more satisfying than a good old piano melody!
It was so difficult to choose a song by Coldplay to put on here, there are just an insane amount of amazing ones to choose from! In the end I went for the one that I think is the most recognisable, and that I definitely have the most amount of memories from.
Note: I'd love to hear your feedback, and if you have any more suggestions of good bands from London. Also if you know of a city/country/etc.. that has a particularly good music scene then please do share, comments are always appreciated!