Los campesinos! (the peasants! – you knew that if you know Spanish.) They sound exactly the way I like! Remind me of Sonic Youth, but much much happier. (Proof: Teenage Riot, one of SY’s lighter songs. It sounds similar to me in spirit.)
Fabulous indie band from Wales! Hear some samples at goear. Or this nice youtube video clip of their famous You! Me! Dancing!. Or, the wikipedia entry. Or, grab the fine song It started with a mixx from KEXP‘s song of the day.