Got a working knowledge of most of those brands! Broadly speaking, they're alternative rock, bit poppy. Lots of hooks, lots of choruses, bit riffy in places. (Black Keys in particular, that last one.) Mumford and Sons are folksy in a sort of earthy way, lots of guitars and banjos and accordions. Florence + the Machine are folksy in a more mystical, celtic kind of way. MGMT are verging on electro, kind of synth-rock, synth-pop, big neon 80s throwbacks, Kings of Leon are straight up alt-rock.
If someone came up to me and said "I love all of these bands," I'd probably recommend them some Biffy Clyro or some Muse. Both big, loud bands that rock uniquely but accessibly.
And I've only heard one song by these guys, so this might be a slightly duff call... but there's a band called Metronomy who have a song called The Look that'd fit in. Rest of their stuff might be good, too?