I'm not a huge Weezer fan, but I do have to say they kick ass live.
As far as rock being dead, you couldn't be further from the truth. The Flatliners, Matt Mays, Against Me!, The Menzingers, The Gaslight Anthem, Red City Radio...I could go on. Plus lots of harder/metal types that don't interest me as much but are objectively good bands. There's plenty to carry the torch, they just aren't topping the charts like they might have back in the day.