Best: AU
Amazing euphoric post-rock.
(honorable mentions: Cats In Paris being incredible, Fuck Buttons making a classic debut album, Of Montreal being a ever-unfolding pop-reinventing revelation, Keyboard Choir being amongst the best live electronic bands I've ever seen)

Worst: TING TINGS
Everything shit about indie in the 00s. Sloganeering, empty-headed Topshop bullshit through and through.
(dishonorable mentions: Bloc Party getting even worse, Lykke Li being massively overrated, Vampire Weekend being fucking awful)